JAWAHARLAL NEHRU PLANETARIUM zsÉåÃAiÀÄ : zsÉåÃAiÀÄ : D
Transcription
JAWAHARLAL NEHRU PLANETARIUM zsÉåÃAiÀÄ : zsÉåÃAiÀÄ : D
JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: D°PÉU¼ À ° À è ªÀÄgÀ¼ÀÄ «©ü£Àß UÀwUÀ¼° À è PɼU À É ¸ÀÄjAiÀÄÄvÀÛzÉ JA§ÄzÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: ¸ÀªÀiÁ£À C¼ÀvA É iÀÄ JgÀqÀÄ D°PÉU¼ À £ À ÀÄß vÉUz É ÀÄPÉƽî, CªÀÅUÀ¼° À è MAzÀgÀ £Á¼ÀPÉÌ ¸ÀÆPÀÛ ªÁå¸ÀzÀ ¦.«.¹. PÉƼÀªA É iÀÄ£ÀÄß ¨sz À ÀæªÁV eÉÆÃr¹. £Á¼ÀzÀ vÀ¼PÀ ÉÌ ¸ÀjºÉÆAzÀĪÀAvÉ PÉƼÀªA É iÀÄ°è MAzÀÄ vÉgª À £ À ÀÄß ªÀiÁrPÉƽî. JgÀqÀÆ D°PÉU¼ À £ À ÀÄß £ÉÃgÀªÁVj¹. PÁqïð MAzÀ£ÀÄß vÉg« À £À ªÀÄÆ®PÀ vÀÆj¸ÀĪÀÅzÀgÉÆA¢UÉ JgÀqÀÆ D°PÉU¼ À ° À è vÀÄA©zÀ ªÀ¸ÀÄÛ ©Ã¼ÀzA À vÉ vÀqÉ»rAiÀÄĪÀ ªÀåªÀ¸ÉÜ ªÀiÁrPÉƽî. D°PÉU¼ À ° À è ¸ÀªÀÄ¥ÀæªÀiÁtzÀ ªÀÄgÀ¼£ À ÀÄß vÀÄA©¹. PÁqïð£ÀÄß ºÉÆgÀU¼ É z É ÀÄ ªÀÄgÀ¼£ À ÀÄß ¸ÉÆÃgÀ®Ä ©r. «ÃQë¹: PÉƼÀªA É iÀÄ£ÀÄß ºÉÆA¢¹gÀĪÀ D°PÉAiÀÄ°èzÀÝ ªÀÄgÀ¼ÀÄ ¨ÉÃUÀ£É ¸ÉÆÃj ºÉÆÃUÀÄvÀÛzÉ. PÁgÀt: ªÀÄgÀ½£À PÀtUÀ¼À £ÀqÀÄªÉ ¸ÀtÚ ¥ÀæªÀiÁtzÀ UÁ½ EzÉ. ªÀÄgÀ¼ÀÄ D°PÉAiÀÄ ªÀÄÆ®PÀ PɼU À É ¸ÁVzÀAvÉ F UÁ½ ªÉÄîPÉÌ ZÀ°¸ÀÄvÀÛzÉ. EzÀjAzÁV D°PÉAiÀÄ vÀÄ¢ JAzÀgÉ PÉƼÀªÉAiÀÄ£ÀÄß eÉÆÃr¹gÀĪÀ eÁUÀz° À è UÁ½AiÀÄ MvÀÛqÀ ªÉÄïÁãUQÀ ÌAvÀ ¸Àé®à vÀUÀÄÎvÀÛz.É F vÀVÎzÀ MvÀÛqª À ÀÅ ªÀÄgÀ½£À PÀtUÀ¼£ À ÀÄß ºÉZÀÄÑ ªÉÃUÀªÁV PɼU À É §gÀĪÀAvÉ ªÀiÁqÀÄvÀÛz.É Objective: To demonstrate the difference in rate of flow of sand through funnels of different lengths of stem. Experiment: Take two identical funnels. Extend the stem of one of them by attaching a PVC pipe that fits in tightly. A slot is cut in the PVC pipe just beneath the stem of the funnel. The two funnels are held vertically and equal amount of sand is poured into both of them. A card, that is inserted in the slot holds the sand in the two funnels from flowing. On removing the card, sand in the two funnels begins to flow out at the same time. Observation: Sand flowing through the funnel with longer stem drains out first. Reason: Sand particles have a small quantity of air in between them. As the sand particles move down in the funnel, this interstitial air moves up. As a result, the air pressure near the bottom of the funnel i.e., where the long pipe is joined to it is slightly lower than the top. This pressure pulls down the sand faster. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¨ÉÃgÉ ¨ÉÃgÉ UÁvÀæzÀ vÀAwUÀ¼À ªÉÄÃ¯É ªÀÄÆqÀĪÀ ¸ÁܬÄà vÀgA À UÀU¼ À £ À ÀÄß vÉÆÃj¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: ¹àÃPÀgï£À ¥Àzg À z À À ªÉÄÃ¯É ªÀÄÆgÀÄ gÀAzsÀæU¼ À ÀļÀî C®Æå«Ä¤AiÀÄA PÉƼÀªA É iÀÄ£ÀÄß Ej¸À¯ÁVzÉ. F gÀAzsÀæU¼ À ÀÄ ªÀÄvÀÄÛ vÀĸÀÄ zÀÆgÀz° À è EªÀÅUÀ½UÉ ¸ÀªÀÄ£ÁzÀ JvÀÛgU À ¼ À ° À è C¼Àªr À ¹gÀĪÀ PÉÆPÉÌU¼ À À ªÀÄzsÉå ªÀÄÆgÀÄ «©ü£Àß UÁvÀæzÀ vÀAwUÀ¼£ À ÀÄß ©VzÀÄ PÀlÖ¯ÁVzÉ. F vÀAwUÀ¼ÀÄ ©UÀĪÁVAiÀÄÆ ¥Àg¸ À ÀàgÀ ¸ÀªÀiÁAvÀgª À ÁVAiÀÄÆ EgÀ°. DåA¦è¥A sóÀ iÀÄgï ªÀÄÆ®PÀ ¹àÃPÀgï C£ÀÄß D¹¯ÉÃlgï£ÉÆA¢UÉ ¸ÀA¥ÀQð¹ PÀA¥À£PÀ ÉÌ M¼À¥r À ¹. «ÃQë¹: ¥Àæw vÀAwAiÀÄ®Æè ¥ÀævÉåÃPÀ vÀgA À UÀzÀÆgÀªÀżÀî ¸ÁܬÄà vÀgA À UÀU¼ À ÀÄ ªÀÄÆqÀÄvÀÛª.É PÁgÀt: vÀAwAiÀÄ ¥Àæw GzÀÝz° À è JµÀÄÖ zÀæªÀågÁ² EzÉ JA§ÄzÀÄ C¯ÉAiÀÄ vÀgA À UÀzÀÆgÀª£ À ÀÄß ¤zsð À j¸ÀÄvÀÛz.É DzÀÝjAzÀ, ¨ÉÃgÉ ¨ÉÃgÉ vÀAwUÀ¼° À è ¨ÉÃgÉ ¨ÉÃgÉ ¸ÁܬÄà vÀgA À UÀU¼ À ÀÄ ªÀÄÆqÀÄvÀÛªÉ. vɼÀî£A É iÀÄ vÀAwAiÀÄ°è vÀgA À UÀzÀÆgÀ ºÉag Ñ ÀÄvÀÛz.É Objective: To demonstrate standing waves on strings of different thicknesses Experiment: Aluminium pipe with three holes is mounted on the membrane of a speaker. Three strings of different thicknesses are strung between the holes and hooks fixed at a distance such that they are taut and parallel to one another. The speaker is driven at certain frequencies by connecting it to an oscillator through an amplifier. Observation: Standing waves of different ‘wavelengths’ are observed on each of the strings. Reason: For a given frequency, the wavelength of sound in a string is inversely proportional to mass per unit length of the string. Therefore, wavelength will be longer in strings of lower mass per unit length. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¸Á§Æ¤£À ¥Àzg À z À ° À è ºÀjzÁqÀĪÀ «£Áå¸ÀU¼ À £ À ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate patterns in flowing soap films. ¥ÀæAiÉÆÃUÀ: f.L. ªÉÊj¤AzÀ MAzÀÄ zÉÆqÀØ DAiÀÄvÁPÁgÀ CxÀªÁ µÀlÄãeÁPÁgÀzÀ ZËPÀlÖ£ÀÄß ªÀiÁrPÉƽî. EzÀ£ÀÄß ¸Á§Æ¤£À zÁæªt À zÀ°è C¢Ý vÉUÉzÀÄ £ÉÃgÀªÁV »rzÀÄPÉƽî. Experiment: A fairly large rectangular or hexagonal wire frame is made using GI wire. This is dipped in a soap solution, taken out and held vertically. «ÃQë¹: ¸Á§Æ¤£À ¥ÀzÀgz À ° À è MAzÉqÉ ¸ÀĽAiÀÄĪÀAvÀºÀ gÀZ£ À É, E£ÉÆßAzÉqÉ ªÉÄîÄäRªÁV ZÀ°¸ÀĪÀ gÀZ£ À ,É »ÃUÉ «©ü£Àß ¨sÁUÀU¼ À ° À è «©ü£Àß gÀZ£ À U É ¼ À ÀÄ PÀAqÀħgÀÄvÀÛª.É Observation: We see different patterns in the flow in different regions of the film including some that show vortices and some that flow upwards. PÁgÀt: ¸Á§Æ¤£À zÁæªt À zÀ ªÉÄïÉäöÊ MvÀq Û ¢ À AzÁVAiÉÄà ¥Àzg À À gÀÆ¥ÀÄUÉƼÀÄîvÀÛz.É zÁæªt À ¸ÀÄjzÀÄ ºÉÆÃzÀAvÉ ªÉÄïÉäöÊ MvÀq Û z À À®Æè ªÀåvÀåAiÀĪÁUÀÄvÀÛz.É EzÀjAzÀ zÀæªÀªÀÅ ºÀjzÁqÀÄvÀÛzÉ. «±ÉõÀªA É zÀg,É ªÉÄïÉäöÊ MvÀÛqÀ ªÀåvÀåAiÀÄ ºÁUÀÆ zÀæªÀzÀ ºÀjAiÀÄÄ«PÉU¼ À À ¸ÀA§AzsÀ ¸ÀAQÃtð jÃwAiÀÄzÀÄ. Reason: The soap film is formed due to the surface tension of the soap solution. As the soap solution drains out, surface tension changes at different places on the film. This causes the fluid to flow. Interestingly, changes in surface tension and the fluid flow affect one another in a complicated manner. ¸Á§Æ¤£À ¥Àzg À PÀ ÉÌ ¸ÀA§A¢ü¹zÀ ¥ÀæAiÉÆÃUÀU½ À UÁV ¸Á§Æ¤£À zÁæªt À vÀAiÀiÁj¸À®Ä ªÀiÁgÀÄPÀmÉÖAiÀÄ°è ®¨sÀå«gÀĪÀ ¦æ¯ï CxÀªÁ «ªÀiï qÁæ¥ï vÀgº À Àz À zÀæªg À ÀÆ¥ÀzÀ ¸Á§Æ£À£ÀÄß §¼À¸À§ºÀÄzÀÄ. 200 «Ä°AiÀĵÀÄÖ ¦æ¯ï CxÀªÁ «ªÀiï qÁæ¥ïUÉ 15°Ã ¤ÃgÀÄ ¸ÉÃj¹zÀgÉ GvÀÛªÀÄ ¥s° À vÁA±À zÉÆgÉAiÀÄÄvÀÛzÉ. For experiments involving soap films, one can use commercial liquid soaps such as Pril or Vim Drop. Mix about 200 ml of it to about 15 litres of water for good results. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ªÀiÁzsÀåªÀĪÉÇAzÀg° À è ¨É¼PÀ ÀÄ ºÁzÀÄ ºÉÆÃUÀĪÀ zÀÆgÀªÀÅ ZÉzÀÄjzÀ ¨É¼QÀ £À §tÚzÀ ªÉÄÃ¯É ©ÃgÀĪÀ ¥ÀjuÁªÀĪÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate the effect of distance travelled by light in a medium and the colour of the scattered light ¥ÀæAiÉÆÃUÀ: MAzÀÄ «ÄÃlgï£ÀµÀÄÖ GzÀÝzÀ UÁf£À vÉÆnÖAiÀÄ°è ¤ÃgÀÄ vÀÄA©¹. MAzÉgq À ÀÄ ºÀ¤ qÉmÁ¯ï ºÁQ PÀ®Q. ¥ÀæPÁ±ÀªÀiÁ£ÀªÁzÀ ©½AiÀÄ ¨É¼PÀ £ À ÀÄß vÉÆnÖAiÀÄ GzÀÝPÀÆÌ ºÁzÀÄ ºÉÆÃUÀĪÀAvÉ ªÀiÁr. Experiment: A glass tank, about 1m long, is filled with water and a few drops of Dettol is added to it and stirred well. A strong beam of white light is shone along the length of the tank. «ÃQë¹: vÉÆnÖAiÉƼÀUÉ PÁtĪÀ ¨É¼ÀQ£À §tÚªÀÅ ¨É¼QÀ £À ªÀÄÆ®PÉÌ ¸À«ÄÃ¥À«gÀĪÉqÉ ¤Ã°AiÀiÁVgÀÄvÀÛz.É zÀÆgÀ«gÀĪÀ PÀqÉ PÉA¥ÁV PÁtÄvÀÛzÉ. Observation: The colour of light in the tank near the light source appears bluish while at the other end it appears reddish. PÁgÀt: qÉmÁ¯ï «Ä²ævÀ ¤ÃgÀÄ PÀ°® zÁæªt À ªÁUÀÄvÀÛz.É CAzÀg,É qÉmÁ¯ï£À ¸ÀtÚ ¸ÀtÚ PÀtUÀ¼ÀÄ ¤Ãj£À°è PÀzr À ºÉÆÃVgÀÄvÀÛªÉ. F PÀtUÀ¼ÀÄ vÀªÀÄä ªÉÄÃ¯É ©zÀÝ ¨É¼PÀ £ À ÀÄß ZÉzÀÄj¸ÀÄvÀÛªÉ. ¤Ã°AiÀÄÄ PÉA¦VAvÀ ºÉZÀÄÑ ZÉzÀÄgÀÄvÀÛzÉ. ºÉZÀÄÑ PÀtUÀ½AzÀ ¨É¼PÀ ÀÄ ZÉzÀÄgÀÄvÁÛ ºÉÆÃzÀAvÉ ¤Ã° §tÚ PÀrªÉÄAiÀiÁUÀÄvÁÛ ºÉÆÃUÀÄvÀÛz.É ºÁUÁV ¨É¼QÀ £À ªÀÄÆ®PÉÌ zÀÆgÀ«gÀĪÀ §¢AiÀÄ°è PÉA¥ÀÄ ¨É¼PÀ ÀÄ ªÀiÁvÀæªÃÉ PÁtÄvÀÛz.É ªÁvÁªÀgt À zÀ°£ è À zsÀƽ£À PÀtUÀ¼ÀÆ EzÉà jÃw ¤Ã° §tÚª£ À ÀÄß ZÉzÀÄj¸ÀĪÀÅzÀjAzÀ¯Éà GzÀAiÀiÁ¸ÀÛªÀiÁ£ÀzÀ ¸ÀÆAiÀÄð PÉA¥ÁV PÁtĪÀÅzÀÄ. Reason: Dettol in water forms a colloid, that is, small particles that are spread all over the liquid. These particles scatter light incident on them. Blue is scattered more than red. As light interacts with more and more particles, the intensity of blue light diminishes. Hence we see red light reaching the end opposite to the light source. A similar behaviour of dust particles in our atmosphere causes sun to appear reddish at sunset or sunrise times. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ªÀļɩ®Äè ªÀÄÆqÀĪÀ ¤gÀƦ¸ÀĪÀÅzÀÄ. vÀvÀ骣 À ÀÄß Objective: To demonstrate the principle behind the formation of a rainbow ¥ÀæAiÉÆÃUÀ: MAzÀÄ zÉÆqÀØ UÁf£À UÉÆüÀzÀ ªÉÄÃ¯É mÁZïð CxÀªÁ ¥ÉÆæePÉ ÀÖgï¤AzÀ §gÀĪÀ ¥ÀæRgÀªÁzÀ ¨É¼QÀ £À QgÀtªÀ£ÀÄß ºÁ¬Ä¹. Experiment: A large sphere of solid glass is mounted on a stand. A narrow beam of intense light from a torch or a projector is shone on it. «ÃQë¹: ¨É¼QÀ £À ªÀÄÆ®zÀ »A§¢UÉ ¸Àé®à zÀÆgÀz° À è »rzÀ ©½AiÀÄ ¥ÀgÀzA É iÀÄ ªÉÄÃ¯É ªÀļɩ®è£ÀÄß PÁt§ºÀÄzÀÄ. Observation: A ‘rainbow’ can be seen on a white screen held at some distance behind the light source. PÁgÀt: UÁf£À UÉÆüÀzÀ M¼ÀPÉÌ ¸ÁUÀĪÀ ¨É¼PÀ ÀÄ ªÀQæèsÀª£ À U À ÉƼÀÄîvÀÛzÉ. UÉÆüÀzÀ M¼ÀUÉ CzÀÄ ¥Àæw¥s° À ¸ÀÄvÀÛzÉ. CzÀgÀ ¸Àé®à ¨sÁUÀ UÉÆüÀ¢AzÀ ºÉÆgÀ§gÀĪÁUÀ ªÀÄvÉÆÛªÉÄä ªÀQæèsÀª£ À U À ÉƼÀÄîvÀÛzÉ. DzÀgÉ ¨ÉÃgÉ ¨ÉÃgÉ §tÚU¼ À ÀÄ ¨ÉÃgÉ ¨ÉÃgÉ ªÀQæèsª À £ À À PÉÆãÀU½ À UÉÉ ¨ÁUÀĪÀÅzÀjAzÀ ©½AiÀÄ ¨É¼PÀ ÀÄ §tÚU¼ À ÁV ¨ÉÃ¥ÀðlÄÖ §tÚ §tÚzÀ PÁªÀÄ£À©°è£A À vÉ PÁtÄvÀÛz.É Reason: Some of the light entering the glass sphere undergoes refraction. Inside the sphere some of it gets reflected. Again, part of this light refracts and emerges out. The angle of refraction is slightly different for different colours (wavelengths). Hence, white light from the source separates out into various colours forming the ‘rainbow’. A similar mechanism with water droplets in the sky leads to a rainbow. ªÁvÁªÀgt À zÀ°g è ÀĪÀ ¤Ãj£À ºÀ¤UÀ¼° À è EzÉà vÀgÀºÀzÀ GAmÁUÀĪÀÅzÀjAzÀ¯Éà ªÀÄÆqÀÄvÀÛzÉ. ¸ÀtÚ ¸ÀtÚ «zÀåªÀiÁ£À ªÀļɩ®Äè JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ªÉÄÃtzÀ §wÛAiÀÄ GjAiÀÄÄ«PÉAiÀÄ°è ¸ÀAªÀº£ À ÀzÀ ¥ÁvÀ檣 À ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate the importance of convection for a burning candle. ¥ÀÀæAiÉÆÃUÀ: GjAiÀÄÄwÛgÀĪÀ ªÉÄÃtzÀ §wÛAiÀÄ£ÀÄß UÁf£À ªÀÄÄA¨sÁUÀ ºÉÆA¢gÀĪÀ ¥ÉnÖUA É iÀÄ°è Ej¹. ¥ÉnÖUA É iÀÄ ªÉÄïÁãUz À ° À è JgÀqÀÄ gÀAzsÀæU¼ À £ À ÀÄß PÉÆgÉzÀÄ, MAzÀÄ gÀAzsÀæPÉÌ aªÀÄtÂAiÀÄ£ÀÄß C¼Àªr À ¹gÀ¨ÃÉ PÀÄ. ªÉÄÃtzÀ §wÛAiÀÄ£ÀÄß aªÀÄtÂAiÀÄ PɼV À j¹. eÁé¯A É iÀÄÄ ¹Ügª À ÁVgÀĪÁUÀ aªÀÄtÂAiÀÄ£ÀÄß PÁqïð¨ÉÆÃqïð¤AzÀ ªÀÄÄaÑ©r. Experiment: A burning candle is placed in a glass-front box. The top surface of the box has two openings – one of which carries a chimney. The burning candle is placed below the chimney. Close the chimney with a cardboard when the candle flame is steady. «ÃQë¹: ªÉÄÃtzÀ §wÛAiÀÄ eÁé¯ÉAiÀÄÄ PÀæªÉÄÃt ªÀÄAPÁV PÉ®ªÉà PÀëtUÀ¼° À è DjºÉÆÃUÀÄvÀÛzÉ. Observation: The candle flame becomes dim and puts off in a few seconds. PÁgÀt: eÁé¯A É iÀÄ ¸ÀÄvÀÛªÀÄÄvÀÛ°£À ¥ÀæzÃÉ ±Àz° À è£À UÁ½ ªÀÄvÀÄÛ zÀº£ À À zÀ GvÀà£ÀßUÀ¼ÀÄ ©¹AiÀiÁVgÀÄvÀÛª.É ¸ÀAªÀº£ À ÀªÀÅ ±ÁR ªÀÄvÀÄÛ zÀº£ À ÀzÀ GvÀà£ÀßUÀ¼£ À ÀÄß eÁ鯬 É ÄAzÀ zÀÆgÀPÉÌ MAiÀÄÄåvÀÛz.É EzÀjAzÁV DQìd£ï M¼ÀUÉÆAqÀ vÀt£ Ú A É iÀÄ UÁ½ D ¸ÁÜ£ª À £ À ÀÄß vÀÄA§ÄvÀÛz.É zÀº£ À QÀ æAiÉÄ ªÀÄÄAzÀĪÀgA É iÀÄÄvÀÛzÉ. aªÀÄtÂAiÀÄ£ÀÄß ªÀÄÄZÀĪ Ñ ÀÅzÀjAzÀ ¸ÀAªÀº£ À À ¸ÀÜVvÀUÉƼÀÄîvÀÛz.É vÀ£ÀÆä®PÀ DQìd£ï£À ¥ÀÆgÉÊPÉAiÀÄÆ ¸ÀÜVvÀUÉƼÀĪ î ÀÅzÀjAzÀ eÁé¯A É iÀÄÄ £ÀA¢ºÉÆÃUÀÄvÀÛz.É Reason: The region surrounding the flame is hot and heats up air and combustion products. Convection transports heat as well as combustion products away from the flame. This causes cooler air with oxygen to replace it which supports combustion and keeps the flame steady. Closing the chimney stops convection and thereby the oxygen supply. As a result of this the flames puts off. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: mÁ£ÁðqÉÆ gÀZ£ À A É iÀÄ°è UÀÄgÀÄvÀz é À ¤gÀƦ¸ÀĪÀÅzÀÄ. (¸ÀĽUÁ½) ¥ÁvÀ檣 À ÀÄß ¥ÀÀæAiÉÆÃUÀ: MAzÀÄ ¥ÁgÀzÀ±ð À PÀ ¹Ã¸ÀA É iÀÄ°è ¤ÃgÀÄ vÀÄA©¹ gÀAzsÀæ«gÀĪÀ ªÀÄÄZÀ¼ Ñ À ºÁQ. ¹Ã¸ÀA É iÀÄ£ÉÆߪÉÄä VgÀQ ºÉÆqɹ vÀ¯ÉP¼ É U À ÁV ªÀiÁr. gÀAzsÀæzÀ ªÀÄÆ®PÀ ¤ÃgÀÄ ¸ÉÆÃgÀÄvÀÛzÉ. ¨Ál°AiÀÄ M¼ÀUÉ ¸ÀĽUÁ½AiÀÄAvÀºÀ gÀZ£ À É ªÀÄÆqÀÄvÀÛz.É Erà ¥ÀæAiÉÆÃUÀª£ À ÀÄß ¥ÀÄ£ÀgÁªÀwð¹, eÉÆvÉUÉ ¸Àé®à JvÀÛg¢ À AzÀ PɼU À É ©Ã¼À®Ä ©r. «ÃQë¹: PɼU À É ©Ã¼ÀĪÁUÀ ¸ÀĽUÁ½AiÀÄAvÀºÀ gÀZ£ À É PÀtägA É iÀiÁUÀÄvÀÛz.É PÁgÀt: JvÀÛgz À ÉÆA¢UÉ MvÀÛqz À À°è PÀæªÉÄÃt §zÀ¯ÁªÀuÉ DUÀĪÀÅzÀjAzÀ¯Éà ¹Ã¸ÀA É iÀįÁèU° À à CxÀªÁ ¥ÀæPÀÈwAiÀįÁèU° À à ¸ÀĽUÁ½AiÀÄ gÀZ£ À A É iÀiÁUÀĪÀÅzÀÄ. E°è MvÀq Û ª À ÀÅ UÀÄgÀÄvÀé CxÀªÁ ¨Ál°AiÉƼÀVgÀĪÀ ¤Ãj£À vÀÆPÀzÀ ªÉÄÃ¯É CªÀ®A©vÀªÁVzÉ. ªÀÄÄPÀÛªÁV ¥Àv£ À U À ÉƼÀÄîªÁUÀ ¹Ã¸ÀÉ ªÀÄvÀÄÛ CzÀgÉƼÀV£À ¤ÃgÀÄ MAzÉà ªÉÃUÉÆÃvÀ̵ð À zÉÆA¢UÉ ©Ã¼ÀÄvÀÛª.É ¥ÀjuÁªÀÄ, ¤ÃgÀÄ vÀÆPÀg» À vÀ ¹ÜwAiÀÄ°ègÀÄvÀÛz.É UÀÄgÀÄvÀézÀ ¥Àæ¨sÁªÀªÉà ±ÀÆ£ÀåªÁ¬ÄvÉA§AvÉ DUÀÄvÀÛz.É ºÁUÁV ¹Ã¸ÀA É iÀÄ M¼ÀUÉ MvÀÛqz À À°è ªÀåvÀåAiÀÄ«®èzÉà ¸ÀĽUÁ½AiÀÄAvÀºÀ gÀZ£ À É ¸ÁzsÀåªÁUÀĪÀÅ¢®è. Objective: To demonstrate the effect of gravity on tornado Experiment: A clear transparent plastic bottle is fitted with a cap with a hole. The bottle is filled up with water, swirled and inverted so that water flows out through the hole. A tornado-like structure sets up in the bottle. Now, drop the bottle from a height. Observation: During the free-fall, the tornadolike structure disappears. Reason: The formation of the tornado-like structure in the bottle as well as the tornado in nature is due to gradual change in pressure from the top of the bottle to its bottom. The pressure depends on gravity or weight of the water column in the bottle. When dropped freely, the bottle and the water in it fall at the same rate and effectively, the weight of water becomes zero. It is as though gravitational influence is absent. So, there will be no pressure differences in the bottle, hence no tornado-like structure. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: mÁæ£ïì¥sóÁªÀÄðgï£À PÁAiÀÄð¤ªÀðºÀuA É iÀÄ°è CzÀgÀ ªÀÄzsÀåzÀ ¸Àg½ À £À ªÉÄïÉäöÊ «¹ÛÃtðzÀ ¥ÁvÀ檣 À ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate the effect of surface area of the core on transformer action ¥ÀÀæAiÉÆÃUÀ: MAzÀÄ ¥Áè¹ÖPï ¨Á©£ï£À ¸ÀÄvÀÛ 20£Éà ¸ÀASÉåAiÀÄ ªÉÊgÀ£ÀÄß 2000 ¨Áj ¸ÀÄwÛ. EzÀÄ ¥ÉæöʪÀÄj ¸ÀÄgÀĽ. 15 ¸É.«ÄÃ. GzÀÝzÀ ¦.«.¹. ¥ÉÊ¥À£ÀÄß ¨Á©£ï£À ªÀÄzsÀå¨sÁUÀPÉÌ vÀÆj¹. E£ÉÆßAzÀÄ aPÀÌ ¨Á©£ï ¸ÀÄvÀÛ CzÉà ªÉÊgÀ£ÀÄß 100 ¨Áj ¸ÀÄwÛ, ªÉÊgï£À vÀÄ¢UÀ¼À £ÀqÀÄªÉ 6v §®â£ÀÄß ¸ÀA¥Àqð¹. ¦.«.¹. ¥ÉÊ¥À£ÀÄß EzÀgÀ ªÀÄÆ®PÀªÀÇ vÀÆj¹. ¥ÉæöʪÀÄj ¸ÀÄgÀĽAiÀÄ£ÀÄß 220v J.¹. ªÉÄÊ£ïì£ÉÆA¢UÉ ¸ÀA¥ÀQð¹. ªÉÆzÀ°UÉ MAzÀÄ zÀ¥ÀàªÁzÀ PÀ©âtzÀ ¸À¯ÁPÉAiÀÄ£ÀÄß ¥ÉÊ¥ï£À ªÀÄÆ®PÀ vÀÆj¹. §¯ïâ£À ¥ÀæRgÀvA É iÀÄ£ÀÄß UÀªÀĤ¹. zÀ¥ÀàªÁzÀ MAzÀÄ ¸À¯ÁPÉAiÀÄ §zÀ°UÉ ºÀ®ªÁgÀÄ ¸ÀtÚ ¸À¯ÁPÉU¼ À £ À ÀÄß Ej¹. FUÀ §®â£ÀÄß UÀªÀĤ¹. Experiment: A coil of 2000 turns of #20 copper wire is wound on a plastic bobbin. This is the Primary coil. Insert a PVC pipe of about 15 cm in length into the centre of the bobbin. Make another coil of 100 turns on another bobbin of a slightly smaller size. Connect a 6v bulb to the 100-turns coil. Insert it into the PVC pipe. Connect the primary coil to 220 V AC Mains. Now, first, insert a solid rod of iron into the PVC pipe and observe the brightness of the bulb. Remove the iron rod and fill the PVC pipe with a number of iron rods of smaller diameter. Again observe the brightness of the bulb. «ÃQë¹: JgÀq£ À A É iÀÄ ¸ÀAzÀ¨ð sÀ zÀ°è §°â£À ¥ÀæRgÀvÉ ªÉÆzÀ°VAvÀ®Æ ºÉZÁÑVgÀÄvÀz Û .É Observation: The bulb brighter in the second case. PÁgÀt: ¸ÀtÚ ¸À¯ÁPÉU¼ À À §¼ÀPɬÄAzÀ ªÀÄzsÀåzÀ ¸Àg¼ À ÀÄUÀ¼À «¹ÛÃtð ºÉZÁѬÄvÀÄ. 100 ¸ÀÄwÛ£À ¸ÀÄgÀĽAiÀÄ°è ¥ÉæÃjvÀ ªÉÇïÉÖÃeï ºÉZÁÑV §®Äâ ¥ÀæRgÀªÁV ¨É¼V À vÀÄ. burns Reason: The area of cross section is more when smaller diameter rods are used. This improves the induced voltage in the 100-turns coils causing the bulb to glow brightly. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¥ÉÊgÉÆðnPï UÁ¥sóÉÊmï£À qÀAiÀiÁPÁAwÃAiÀÄ UÀÄtªÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀÀæAiÉÆÃUÀ: ¥ÉÊgÉÆðnPï UÁæ¥sóÉÊmï JA§ÄzÀÄ EAUÁ®ªÀ£ÀÄß ¥Àzg À ÀÄ ¥Àzg À U À ¼ À ÁV gÀÆ¥ÀÄUÉƼÀÄîªA À vÉ ªÀiÁr, vÀAiÀiÁj¹zÀ ªÀ¸ÀÄÛ. ±ÁR ªÀÄvÀÄÛ «zÀÄåvïUÀ¼À GvÀÛªÀÄ ªÁºÀPª À ÁzÀ EzÀÄ qÀAiÀiÁPÁAwÃAiÀÄ ªÀ¸ÀÄÛ«UÉ GvÀÛªÀÄ GzÁºÀgu À .É ¥sg óÉ ÉÆÃPÁAwÃAiÀÄ ªÀ¸ÀÄÛU¼ À ÀÄ PÁAvÀzq É É DPÀ¶ð¸À®àqÀÄvÀª Û É. DzÀg,É qÀAiÀiÁPÁAwÃAiÀÄ ªÀ¸ÀÄÛU¼ À ÀÄ «PÀ¶ð¸À®àqÀÄvÀÛªÉ. F ¥ÀæAiÉÆÃUÀzÀ°è JgÀqÀÄ UÁæ¥sóÉÊmï ºÁ¼ÉU¼ À À £ÀqÀÄªÉ MAzÀÄ PÁAvÀ«zÉ. ªÉÄïÁãUz À À UÁæ¥sóÉÊmï ºÁ¼ÉVAvÀ ¸Àé®àªÃÉ JvÀÛgz À À °è ªÀÄvÉÆÛAzÀÄ PÁAvÀ«zÉ. EªÀÅUÀ¼À £ÀqÀÄ«£À CAvÀgª À £ À ÀÄß ¸ÀÆPÀÛªÁV CtÂUÉƽ¹ UÁæ¥sóÉÊmï ºÁ¼ÉU¼ À À £ÀqÀÄ«gÀĪÀ ¥ÉÊgÉÆðnPï UÁ¥sóÉÊmï PÁAvÀª£ À ÀÄß vÉîĪÀAvÉ ªÀiÁqÀ§ºÀÄzÀÄ. PÁgÀt: UÁæ¥sóÉÊmï ºÁ¼ÉAiÀÄ ªÉÄðgÀĪÀ PÁAvÀ ºÁ¼ÉU¼ À À £ÀqÀÄ«gÀĪÀ PÁAvÀª£ À ÀÄß DPÀ¶ð¸ÀÄvÀÛzÉ E®èªÉà «PÀ¶ð¸ÀÄvÀÛzÉ. £ÀqÀÄ«gÀĪÀ PÁAvÀ ªÉÄÃ¯É §AzÀgÀÆ PɼU À É ºÉÆÃzÀgÀÆ UÁæ¥sóÉÊmï ºÁ¼É¬ÄAzÀ «PÀ¶ð¸À®àqÀÄvÀz Û À.É ºÁUÁV CzÀÄ CªÉgq À g À À £ÀqÀÄªÉ vÉîÄvÀÛz.É Objective: To demonstrate the diamagnetism in Pyrolytic Graphite. Experiment: Pyrolytic Graphite is an artificially produced material by carefully depositing carbon to form layers. It has very high thermal and electrical conductivity and substantial diamagnetism. A diamagnetic substance is always repelled by strong magnets. Ferromagnets are always attracted by magnets. In this experiment, we have pyrolytic graphite sheets separated by a small distance. A strong magnet is placed between them. Another strong magnet is placed a little above the top layer of pyrolytic graphite. When the distances between magnets and between the graphite layers are properly adjusted, the magnet between the layers levitates! Reason: The magnet at the top attracts or repels the lower one. As the lower magnet moves up or down towards one of the graphite layers, it is repelled by both layers. Therefore, it levitates. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¸Á§Æ¤£À ¥Àzg À z À À ªÉÄÃ¯É vÀgA À UÀU¼ À £ À ÀÄß vÉÆÃj¸ÀĪÀÅzÀÄ. ¸ÁܬÄà Objective: To demonstrate standing waves on a soap film ¥ÀæAiÉÆÃUÀ: f.L. ªÉÊj¤AzÀ ¸ÀĪÀiÁgÀÄ 10 ¸É.«Äà X 25 ¸É.«ÄÃ. C¼ÀvA É iÀÄ DAiÀÄvÁPÁgÀzÀ ZËPÀlÖ£ÀÄß ªÀiÁrPÉƽî. zÀæªg À ÀÆ¥ÀzÀ ¸Á§Æ¤£À zÁæªt À zÀ°è EzÀ£ÀÄß C¢Ý JwÛzg À É ¸Á§Æ¤£À ¥Àgz À É gÀÆ¥ÀÄUÉƼÀÄîvÀÛz.É F ZËPÀlÖ£ÀÄß CqÀدÁVj¹, CzÀgÀ ¸ÀªÀÄvÀ®PÉÌ ®A§ªÁVgÀĪÀAvÉ ºÀUÀÄgÀªÁV DAzÉÆî£ÀPÉÌ M¼À¥r À ¹. Experiment: A rectangular wire frame of a convenient size, say 10cm X 25 cm, is made out of thick GI wire. It is dipped in a soap solution made using commercially available liquid soap with water. A soap film will formed by the wireframe. Hold the wireframe in a horizontal position and oscillate the frame in a vertical plane gently. «ÃQë¹: ¨ÉÃgÉ ¨ÉÃgÉ PÀA¥À£ÁAPÀU¼ À ° À è Czsð À vÀgA À UÀ, ¥ÀÆtð vÀgA À UÀ CxÀªÁ MAzÀƪÀgÉ vÀgA À UÀ ªÀÄÆqÀĪÀÅzÀ£ÀÄß PÁt§ºÀÄzÀÄ. Observation: We see a half wave, a full wave or one-and-a-half waves on the soap film at various frequencies, PÁgÀt: ¸Á§Æ¤£À ¥Àzg À z À À ¨ÉÃgÉ ¨ÉÃgÉ ¨sÁUÀU¼ À ÀÄ ¸ÁÜ£À ¥À®èlzÀ°è ¸Àé®àªÃÉ ¸ÀªÀÄAiÀÄzÀ CAvÀg« À zÉ. EzÀjAzÁV vÀgA À UÀ gÀÆ¥ÀÄUÉƼÀÄîvÀÛz.É «gÀÄzÀÞ ¢QÌ£° À è ¥À¸j À ¸ÀÀĪÀ vÀgA À UÀU¼ À ÀÄ ªÀåwPÀgt À UÉÆAqÀÄ ¸ÁܬÄà vÀgA À UÀU¼ À ÀÄ ªÀÄÆqÀÄvÀÛª.É Reason: Different parts of the film get displaced in the vertical direction at slightly different time. This constitutes a wave. As we oscillate the frame at a constant frequency, a standing wave is created due to interference of waves that propagate in opposite directions. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¨É¼QÀ £À ªÀåwPÀgt À ªÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀÀæAiÉÆÃUÀ: ¨ÉÃgÉ ¨ÉÃgÉ wædå«gÀĪÀ JgÀqÀÄ ¦Ã£À ªÉÄïÉäöÊUÀ¼£ À ÀÄß MAzÀgÀ ªÉÄïÉÆA¢j¹, CªÀÅUÀ¼À ªÀÄzsÀå ©AzÀÄ«¤AzÀ ¸Àé®à ¥ÀPÀÌPÉÌ ¯ÉøÀgï QgÀtUÀ¼£ À ÀÄß ºÁ¬Ä¹. ºÀ®ªÁgÀÄ ¨Áj ¥ÀæAiÀÄwß¹zÀ ªÉÄÃ¯É ¤jÃQëvÀ ¥s° À vÁA±À zÉÆgÉAiÀÄÄvÀÛz.É «ÃQë¹: ¯ÉøÀgï QgÀt ¤UÀ¢AiÀiÁzÀ ¸ÁÜ£z À À ªÉÄÃ¯É ¥Àv£ À U À ÉÆAqÁUÀ, ¥Àæw¥s° À vÀ ¨É¼QÀ £À ¥Àxz À À °è Ej¹zÀ ¥Àgz À A É iÀÄ ªÉÄÃ¯É PÀ¥ÀÄà ªÀÄvÀÄÛ §tÚzÀ GAUÀÄgÀU¼ À ÀÄ ªÀÄÆqÀÄvÀÛª.É PÁgÀt: D¥ÁvÀ ¨É¼PÀ ÀÄ JgÀqÀÄ ¦Ã£À ªÉÄïÉäöÊUÀ½AzÀ ¥Àæw¥s° À vÀUÉƼÀÄîvÀÛz.É D ªÉÄïÉäöÊUÀ¼À £ÀqÀÄ«£À CAvÀgÀ ¸Àj¸ÀĪÀiÁgÀÄ ¨É¼QÀ £À vÀgA À UÀzÀÆgÀzÀ¶ÖzÁÝU,À ¥Àgz À A É iÀÄ ªÉÄÃ¯É »ÃUÉ C£ÀÄPÀæªÀĪÁV PÀ¥ÀÄà ªÀÄvÀÄÛ §tÚzÀ GAUÀÄgÀU¼ À £ À ÀÄß PÁtÄvÉÛêÉ. «zsÁAiÀÄPÀ ªÀåwPÀgt À zÀ ¸ÀܼU À ¼ À ÀÄ §tÚªÁV, «zÀéA¸ÀPÀ ªÀåwPÀgt À zÀ ¸ÀܼU À ¼ À ÀÄ PÀ¥ÁàV EgÀÄvÀÛªÉ. Objective: To interference of light demonstrate Experiment: Two convex surfaces of slightly different radii of curvatures are placed one above the other. Shine light from a Laser pointer at a point close to centre but slightly away from it. You may have to get the desired result by trial-and-error method to begin with. Observation: When position of the light beam striking the two curved surfaces if just right, one can see concentric rings of light and dark region on a screen placed in the path of the reflected light. Reason: The incident light is actually reflected by two convex surfaces. Where the gap between the two surfaces is comparable wavelength of light used, we see a series of dark and light regions alternating on the screen. The bright regions correspond to positions of constructive interference and those of dark regions to destructive interference. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: «zÀÄåvÁÌAwÃAiÀÄ ¥ÉæÃgÀuU É É ¸ÀÄgÀĽ ªÀÄvÀÄÛ PÁAvÀzÀ £ÀqÀÄ«£À ¸Á¥ÉÃPÀë ZÀ®£É CªÀ±ÀåPÀ JA§ÄzÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: ¥Áè¹ÖPï ¨Á©£ï£À ¸ÀävÀÛ 20£Éà UÉÃeï ¸ÀASÉåAiÀÄ vÁªÀÄæzÀ vÀAwAiÀÄ£ÀÄß 150 ¨Áj ¸ÀÄwÛ. F ¸ÀÄgÀĽAiÀÄ£ÀÄß UÁå®é£ÉÆà «ÄÃlgï£ÉÆA¢UÉ ¸ÀA¥ÀQð¹. ¸ÀÄgÀĽAiÀÄ£ÀÄß ¹Ügª À ÁVj¹, PÁAvÀª£ À ÀÄß EzÀgÀ ªÀÄÆ®PÀ ºÁzÀĺÉÆÃUÀĪÀAvÉ ªÀiÁr. £ÀAvÀgÀ PÁAvÀª£ À ÀÄß ¹Ügª À ÁVj¹, ¸ÀÄgÀĽAiÀÄ£ÀÄß ZÀ°¹. (¨Á©£ï£À ªÀÄzsÀå ¨sÁUÀPÉÌ PÁAvÀªÀÅ §AzÀÄ ºÉÆÃUÀĪÀAvÁUÀ¨ÉÃPÀÄ). ªÀÄÆgÀ£A É iÀÄ ¨Áj, ¸ÀÄgÀĽAiÀÄ M¼ÀUÃÉ PÁAvÀª£ À ÀÄß Ej¹, JgÀq£ À ÀÆß MnÖUÉ PɼU À É ©r. «ÃQë¹: ªÉÆzÀ¯g É q À ÀÄ ¸ÀAzÀ¨ð sÀ zÀ°è ¥ÉæÃjvÀ «zÀÄåvï£À ¸ÀÆZÀPª À ÁV UÁå®é£ÉÆà «ÄÃlgï£À°è «PÉëÃ¥Àt GAmÁUÀÄvÀÛzÉ. ªÀÄÆgÀ£A É iÀÄ ¸ÀAzÀ¨ð sÀ zÀ°è CzÀÄ GAmÁUÀĪÀÅ¢®è. PÁgÀt: ¸ÀÄgÀĽAiÀÄ ªÀÄÆ®PÀ ºÁAiÀÄĪÀ PÁAwÃAiÀÄ C©üªÁºÀz° À è (flux) §zÀ¯ÁªÀuA É iÀiÁzÁUÀ ªÀiÁvÀæªÉà ¸ÀÄgÀĽAiÀÄ°è ¥ÉæÃjvÀ «zÀÄåvï GAmÁUÀ®Ä ¸ÁzsÀå. F §zÀ¯ÁªÀuU É É ¸ÀÄgÀĽ ªÀÄvÀÄÛ PÁAvÀzÀ £ÀqÀÄªÉ ¸Á¥ÉÃPÀë ZÀ®£É Cw CªÀ±Àå. Objective: To demonstrate that relative motion between a coil and a magnet is necessary for electromagnetic induction. Experiment: A coil of about 150 turns is made by winding a #20 copper wire. The coil is connected to a galvanometer. First, a strong magnet is dropped through the stationary coil. Next we keep the magnet stationary and drop the coil such that the central gap in the bobbin moves with the stationary magnet at the centre. Thirdly, we hold the magnet at the top end of the coil and drop both simultaneously. Observation: The galvanometer shows deflection, indicating a current induced in the coil in the first two cases but no deflection in the third. Reason: Current is induced in the coil when the magnetic flux (‘lines of force’) changes with respect to the coil. This happens only if there is a relative motion between the coil and the magnet. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: MAzÀÄ vÀmÉÖAiÀÄ ªÉÄÃ¯É ªÀÄÆqÀĪÀ ¸ÁܬÄà vÀgA À UÀU¼ À £ À ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: MAzÀÄ ZËPÁPÁgÀzÀ C®Æå«Ä¤AiÀÄA vÀmÉÖAiÀÄ ªÀÄzsÀå¨sÁUÀPÉÌ ®A§ªÁV D¸ÀgU É ÉÆî£ÀÄß Ej¸À¯ÁVzÉ. vÀmA ÉÖ iÀÄ ªÉÄÃ¯É ªÀÄgÀ¼£ À ÀÄß ZÀĪÀÄÄQ¹, CAZÀ£ÀÄß ªÀAiÉÆð£ï£À PÀªÀiÁ¤¤AzÀ GfÓ vÀmÉÖAiÀÄ£ÀÄß PÀA¦¸ÀĪÀAvÉ ªÀiÁr. C¸ÀÛªÀå¸ÀÛªÁV ºÀgr À PÉÆArzÀÝ ªÀÄgÀ¼ÀÄ ¸ÀÄAzÀgÀ «£Áå¸ÀªÁV ªÀiÁ¥ÀðqÀÄvÀÛzÉ. PÁèr¤ JA§ «eÁÕ¤AiÀÄÄ EAvÀºÀ «£Áå¸ÀU¼ À À CzsÀåAiÀÄ£À ªÀiÁrzÀ ªÉÆzÀ°UÀ. ºÁUÁV, EªÀÅUÀ½UÉ PÁèr¤ avÀæU¼ À ÀÄ JAzÀÄ ºÉ¸g À ÀÄ. PÁgÀt: PÀªÀiÁ¤¤AzÀ GfÓzÁUÀ vÀmA ÉÖ iÀÄÄ PÀA¦¸ÀÄvÀz Û É. DzÀg,É vÀmÉÖAiÀÄ ¨ÉÃgÉ ¨ÉÃgÉ ¨sÁUÀU¼ À ° À è ¥ÁgÀ ¨ÉÃgÉ ¨ÉÃgÉAiÀiÁVgÀÄvÀÛz.É ¥ÁgÀªÀÅ ±ÀÆ£Àå«gÀĪÀ ¸ÁÜ£U À ¼ À ° À è ªÀÄgÀ½£À PÀtUÀ¼ÀÄ ±ÉÃRgÀUÉƼÀÄîvÀÛªÉ. vÀmÉÖAiÀÄ DPÁgÀ, ªÀ¸ÀÄÛ«£À ¸ÁAzÀævÉ ªÀÄvÀÄÛ PÀªÀiÁ¤¤AzÀ GAmÁzÀ PÀA¥À£U À ¼ À ÀÄ ±ÀÆ£Àå¥ÁgÀzÀ ¸ÁÜ£U À ¼ À £ À ÀÄß ¤zsð À j¸ÀÄvÀÛª.É Objective: To demonstrate standing waves in a plate Experiment: The centre of a square aluminium plate is fixed to a stand such that the plate is horizontal. Sprinkle some fine sand on the plate. Excite the plate by bowing one of the edges with a violin Bow. The randomly sprinkled particles of sand arrange into beautiful patterns known as Chladni Figures, after the person who studied them. Reason: Bowing the plate sets the plate into vibration. The amplitude of vibration is not the same everywhere on the plate. Sand particles collect in regions of zero amplitude, that is, where there are no vibrations. The regions of zero amplitude depend on factors such as the shape of the plate, frequency of vibration and density of the material of the plate. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: DgÀA¨sÀ ªÉÃUÀªÃÉ ¥ÀæPÃÉë ¥ÀåzÀ ªÁå¦ÛAiÀÄ£ÀÄß ¤zsð À j¸ÀÄvÀÛzÉ JA§ÄzÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: bÁAiÀiÁavÀæz° À è PÁtĪÀAvÉ ¥Áè¹ÖPï PÉùAUï ¥ÀnÖAiÀÄ£ÀÄß ºÀ®UÉAiÉÆAzÀgÀ ªÉÄÃ¯É ®UÀwÛ¸¯ À ÁVzÉ. ¹Öïï UÉÆüÀªÉÇAzÀ£ÀÄß ¥ÀnÖAiÀÄ ªÉÄÃ¯É MAzÀÄ ¤¢ðµÀÖ ¸ÁÜ£¢ À AzÀ JµÉÖà ¨Áj GgÀĽ¹zÀgÀÆ CzÀÄ ºÀ®UÉAiÀÄ vÀ¼z À ° À ègÀĪÀ MAzÀÄ gÀAzsÀæzÉƼÀPÉÌà §AzÀÄ ©Ã¼ÀÄvÀz Û .É PÁgÀt: ¥ÀæPÉëævÀ ªÀ¸ÀÄÛ PÀæ«Ä¸ÀĪÀ ¸ÀªÀÄvÀ® zÀÆgÀª£ À ÀÄß CzÀgÀ ªÁå¦Û JAzÀÄ PÀgA É iÀÄÄvÉÛêÉ. EzÀÄ DgÀA¨s¢ À AzÀ £É® ªÀÄÄlÖ®Ä ¨ÉÃPÁUÀĪÀ ¸ÀªÀÄAiÀÄ ªÀÄvÀÄÛ ¸ÀªÀÄvÀ®zÀ ¢QÌ£° À ègÀĪÀ ªÉÃUÀzÀ ¨sÁUÀzÀ UÀÄt®§Þ. £ÀªÀÄä ¥ÀæzÀ²ðPÉAiÀÄ°è UÉÆüÀªÀÅ UÁ½AiÀÄ°è PÀæ«Ä¸ÀĪÀ ¸ÀªÀÄAiÀÄ ¤²Ñvª À ÁVzÉ. DzÀÝjAzÀ, ªÁå¦ÛAiÀÄ°è ªÀåvÁå¸À §gÀ¨ÉÃPÉAzÀgÉ CzÀÄ ªÉÃUÀzÀ ¸ÀªÀÄvÀ® ¨sÁUÀ¢AzÀ¯ÃÉ DVgÀ¨ÉÃPÀÄ. UÉÆüÀª£ À ÀÄß AiÀiÁªÀ ¸ÁÜ£¢ À AzÀ GgÀļÀ®Ä ©qÀÄvÉÛÃªÉ JA§ÄzÀÄ CzÀgÀ ªÉÃUÀª£ À ÀÄß ¤zsð À j¸ÀÄvÀÛzÉ. E°è MAzÉà ¸Àܼ¢ À AzÀ GgÀļÀ®Ä ©qÀĪÀÅzÀjAzÀ CzÀgÀ ªÁå¦ÛAiÀÄÄ ¤²ÑvÀªÁVzÉ. Objective: To demonstrate that the range of a projectile depends on the velocity of launch Experiment: A smooth ramp is made out of a plastic casing pipe and fixed to a vertical board as shown in the photograph. A steel sphere repeatedly rolled from a fixed point on the ramp always passes through the hole at the bottom of the board. Reason: Range is the horizontal distance that a projectile covers. It is the product of horizontal component of velocity and the time for which the projectile stays in flight. The position of release of the steel sphere decides the velocity. Since the time for which the sphere stays in air is constant in our set up, the difference in range covered is due to difference in velocity. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: J¯ÉPÁÖ礣À vÀgA À UÀ ¸Àé¨sÁªÀª£ À ÀÄß ¸ÁzÀȱÀvA É iÀÄ ªÀÄÆ®PÀ ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate the wave nature of electrons through analogy. ¥ÀæAiÉÆÃUÀ: MAzÀÄ vɼÀîV£À vÀAwAiÀÄ£ÀÄß ªÀÈvÁÛPÁgÀPÉÌ ¨ÁV¹, ¹àÃPÀgï£À ªÉÄÃ¯É ¤°è¹. F ¹àÃPÀgïC£ÀÄß DA¥Àè¥A sóÀ iÀÄgï£À ªÀÄÆ®PÀ D¹¯Éãlgï£ÉÆA¢UÉ ¸ÀA¥ÀQð¹. vÀAw¬ÄAzÀ ªÀiÁrzÀ ªÀÈvÀÛª£ À ÀÄß PÀA¥À£PÀ ÉÌ M¼À¥r À ¹. Experiment: A thin circular loop of thin wire is mounted on a speaker. The speaker is driven by an oscillator through an amplifier. The loop of wire is set into vibration using the oscillator. «ÃQë¹: ªÀÈvÁÛPÁgÀzÀ vÀAwAiÀÄ°è ¸ÁܬÄà vÀgA À UÀU¼ À ÀÄ ªÀÄÆqÀĪÀÅzÀjAzÀ £ÉÆÃqïUÀ¼ÀÄ (¸ÁÜ¬Ä ©AzÀÄUÀ¼ÀÄ) ªÀÄvÀÄÛ DAn£ÉÆÃqïUÀ¼ÀÄ gÀÆ¥ÀÄUÉƼÀÄîvÀÛª.É Observation: We observe a standing wave pattern with nodes (points of zero displacement) and antinodes along the circumference of the loop. ¸ÁzÀȱÀv:É MAzÀÄ ¤¢ðµÀÖ wædåzÀ ªÀÈvÀÛz° À è ªÀÄÆqÀĪÀ ¸ÁܬÄà vÀgA À UÀU¼ À ° À è 1, 2, 3.................. F jÃw ¸ÀA¥ÀÆtð vÀgA À UÀU¼ À ÀÄ ªÀiÁvÀæ ªÀÄÆqÀ®Ä ¸ÁzsÀå. J¯ÉPÁÖç£ï£À ZÉÊvÀ£Àå, CzÀgÀ vÀgA À UÀzÀÆgÀzÀ ªÉÄÃ¯É Dzsj À ¹zÉ. vÀgA À UÀzÀÆgÀU¼ À ÀÄ «ªÀPÀÛ (descrete) ªÁzÀÄzÀjAzÀ, ZÉÊvÀ£ÀåUÀ¼ÀÆ «ªÀPÀÛªÁVªÀ.É CAvÉAiÉÄà F ¥Àæz² À ðPÉAiÀÄ°è 2, 3, 4.......... F jÃwUÀ¼À ¸ÁÜ¬Ä ©AzÀÄUÀ¼ÀÄ gÀÆ¥ÀÄUÉƼÀÄîvÀÛª.É Analogy: For a standing wave to form in a circle of a given radius, only integral number of wavelengths is possible. Because the electron energies depend on their wavelengths and the wavelengths are discrete, the allowed energies must also be discrete. In this model we see two nodes, three nodes, four nodes and so on…. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: J.¹. ªÉÇïïÖ«ÄãlgïUÀ¼ÀÄ K£À£ÀÄß C¼ÉAiÀÄÄvÀÛªÉ JA§ÄzÀ£ÀÄß CxÉÊð¹PÉƼÀÄîªÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: 20£Éà UÉÃeï ¸ÀASÉåAiÀÄ vÁªÀÄæzÀ vÀAwAiÀÄ£ÀÄß ¥Áè¹ÖPï PÉƼÀªÉAiÀÄ ¸ÀÄvÀÛ 1000 ¸ÀÄvÀÄÛ ¸ÀÄwÛ PÉƼÀªA É iÀÄ M¼ÀUÉ ±ÀÄzÀÞ PÀ©âtzÀ ¸Àg¼ À £ À ÀÄß vÀÆj¹. 1KΩ£À 2 gÉÆÃzsPÀ U À ¼ À £ À ÀÄß ¸ÀªÀiÁAvÀgª À ÁV ¸ÀA¥ÀQð¹ ¸ÉƯɣÁAiÀiïØ£À ¸ÀÄvÀÛ GAUÀÄgÀzA À vÉ zÀÈqsÀªÁV PÀÆj¹. ¸ÀÄgÀĽAiÀÄ£ÀÄß 220V J.¹. ªÉÄÊ£ïìUÉ ¸ÀA¥ÀQð¹. gÉÆÃzsÀPU À ¼ À £ À ÀÄß ¸ÀA¥ÀQð¹gÀĪÀ ©AzÀÄUÀ¼À £ÀqÀÄ«£À «¨sª À À ª£ À ÀÄß J.¹. ªÉÇïïÖ«ÄÃlgï£À°è C¼É¬Äj. F ¸ÀAzÀ¨ð sÀ zÀ°è ªÉÇïïÖ«ÄÃlgÀ£ÀÄß D¸ÀÄ¥Á¹£À ¨ÉÃgÉ ¨ÉÃgÉ ¸ÁÜ£U À ¼ À ° À èlÖgÉ CzÀÄ vÉÆgÀĪÀ ªÉÇïÉÖÃeï ¸ÀºÀ §zÀ¯ÁUÀÄvÀÛz!É ! PÁgÀt: ªÉÇïïÖ «ÄÃlgïUÀ¼ÀÄ ¥ÉÆæèïUÀ¼£ À ÉÆß¼ÀUÉÆAqÀ ¸ÀQðmï£ÀÀ ¥ÀxÀz° À ègÀĪÀ E.JªÀiï.J¥sóï. C£ÀÄß C¼ÉAiÀÄÄvÀÛªA É iÉÄà ºÉÆgÀvÀÄ «zÀÄåvï «¨sÀªª À £ À Àß®è. «zÀÄåvï PÉëÃvÀæz° À è §zÀ¯ÁªÀuÉ E®èzÀ r¹ «zÀÄåvï ¥ÀæªÀ»¸ÀÄwÛgÀĪÀ ¸ÀAzÀ¨sð À zÀ°è EzÉà «zÀÄåvï «¨sª À ª À £ À ÀÄß ¤ÃqÀÄvÀÛzÉ. E°ègÀĪÀ gÉÆÃzsPÀ U À ¼ À ° À è «ÄÃlgï£À ¥ÉÆæèïUÀ¼ÀÆ ¸ÉÃjªÉ. CªÀÅ ¸ÉƯɣÁAiÀiïØ£À §zÀ¯ÁUÀÄwÛgÀĪÀ «zÀÄåvÁÌAwÃAiÀÄ PÉëÃvÀæz° À èª.É E°è ¨ÉÃgÉ ¨ÉÃgÉ ¸ÁÜ£U À ¼ À ° À è ¨ÉÃgÉ ¨ÉÃgÉ «zÀÄåvï PÉëÃvÀæ«zÉ JAzÀÄ vÉÆÃj¸ÀÄwÛz.É Objective: To understand what the AC Voltmeters measure. Experiment: Make a solenoid of 1000 turns of #20 copper wire on a plastic pipe. The pipe is filled with a soft iron core. Two resistors of, say 1kΩ, are connected in parallel to form a ring that tightly fit around the solenoid, as shown. The coil is connected to 220V AC. The potential difference between the points of contact of the two resistors is measured with an AC voltmeter. The measurement is carried out between the same two points but the voltmeter is moved to a new position. Now, the voltmeter reading will be different!!! Reason: The resistors have been placed in a changing electromagnetic field around the solenoid. What the voltmeters measure is not the potential difference but the EMF along the path of the circuit which includes the probes. In an unchanging electric field, as in DC, this measurement corresponds to potential difference itself. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ¤Ã¼À C¯ÉAiÀÄ ¸ÀAZÁgÀuA É iÀÄ£ÀÄß ¸ÁzÀȱÀvA É iÀÄ ªÀÄÆ®PÀ ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: ¸ÀĪÀiÁgÀÄ 20 qÉÆãÀmï DPÁgÀzÀ ¸ÉgÁ«ÄPï PÁAvÀU¼ À £ À ÀÄß PÀAZÀÄ CxÀªÁ ¥Áè¹ÖPï PÀA©AiÀÄ ªÀÄÆ®PÀ vÀÆj¹. PÁAvÀU¼ À ÀÄ MAzÀPÉÆÌAzÀÄ «PÀ¶ð¸ÀĪÀAwgÀ¨ÉÃPÀÄ. D PÀA©AiÀÄ£ÀÄß CqÀدÁV »rzÀÄ ¤zsÁ£ÀªÁV PÉÆ£ÉAiÀÄ°ègÀĪÀ MAzÀÄ PÁAvÀª£ À ÀÄß ¸Àé®àªÉà dgÀÄV¹. «ÃQë¹: ªÀÄvÉÆÛAzÀÄ vÀÄ¢AiÀĪÀgU É ÀÆ EgÀĪÀ «ÄPÉ̯Áè PÁAvÀU¼ À ÀÆ MAzÁzÀ ªÉÄïÉÆAzÀÄ dgÀÄUÀÄvÀÛª.É ¸ÁzÀȱÀv:É MAzÀÄ vÀÄ¢AiÀÄ°è PÁAvÀªÀ£ÀÄß dgÀÄV¸ÀĪÀ ªÀÄÆ®PÀ GAlĪÀiÁrzÀ ªÀåvÀåAiÀÄ CzÉà ¢QÌ£À°è ¸ÁV E£ÉÆßAzÀÄ vÀÄ¢AiÀÄ£ÀÄß vÀ®Ä¥ÀÄvÀÛzÉ. E°è ¥ÀæwAiÉÆAzÀÄ PÁAvÀªÀÇ ZÉÊvÀ£ÀåªÀ£ÀÄß vÀ£Àß ¥ÀPÀÌz° À ègÀĪÀÅzÀPÉÌ ªÀUð À ªÀiÁr vÀ£ÀÆä®PÀ vÀgA À UÀzÀ ¸ÀAZÀgu À U É É PÁgÀtªÁUÀĪÀ PÀtzÀAvÉ ªÀwð¸ÀÄvÀÛz.É zsÀé¤ vÀgA À UÀU¼ À £ À ÀÄß UÁ½AiÀÄ PÀtUÀ¼ÀÄ »ÃUÉAiÉÄà ªÀUÁð¬Ä¸ÀÄvÀÛª.É Objective: To provide an analogy to the propagation of longitudinal waves. Experiment: Place about 20 circular, ceramic magnets with a hole along a nonmagnetic rod such as brass or plastic. Each magnet must repel the neighbouring two magnets. Holding the non-magnetic rod horizontally, gently displace the extreme magnet. Observation: Successively, each magnet shows a small displacement – all the way to the other end of the rod. Analogy: The disturbance caused by displacing the magnet at one end travels in the direction of the disturbance. Here each magnet behaves like a particle that transfers energy to the immediate neighbour resulting in the propagation of a pulse or wave. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: PÉmÁ°¸ïÖU¼ À À §¼ÀPɬÄAzÀ gÁ¸ÁAiÀĤPÀ QæAiÉÄAiÀÄ ªÉÃUÀª£ À ÀÄß §zÀ°¸À§ºÀÄzÀÄ JA§ÄzÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ: ¸ÁzsÁgÀt vÁ¥ÀªÀiÁ£À ªÀÄvÀÄÛ MvÀÛqz À ° À è ºÉÊqÉÆæÃd£ï ¥ÀgÁPÉìöÊqï JA§ gÁ¸ÁAiÀĤPÀªÀÅ §ºÀ¼À ¤zsÁ£ÀªÁV ¤ÃgÀÄ ªÀÄvÀÄÛ DQìd£ï DV «¨sd À £ÉUÉƼÀÄîvÀÛz.É anPÉAiÀĵÀÄÖ ¯Éqï DPÉìöÊqÀ£ÀÄß ¸ÉÃj¹zÀgÉ F «¨sÀd£ÉAiÀÄ UÀwAiÀÄÄ ºÉZÁÑUÀÄvÀÛz.É Objective: To demonstrate that the rate of a chemical reaction can be altered by catalysts Experiment: Hydrogen peroxide decomposes into water and oxygen under normal temperature and pressure. This is a very slow reaction. Adding a pinch of lead oxide increases the rate of the reaction. «ÃQë¹: ¯Éqï DPÉìöÊqï ºÁPÀÄwÛzÀÝAvÉAiÉÄà ªÉÃUÀªÁV £ÉÆgÉ §gÀÄvÀÛz.É F gÁ¸ÁAiÀĤPÀ QæAiÉÄ £ÀqA É iÀÄÄwÛgÀĪÀ ¥ÀætÁ®zÀ ªÉÄÃ¯É QrUÀrØAiÀÄ£ÀÄß »rzÀgÉ CzÀÄ ºÉZÀÄÑ ¥ÀæPÁ±ÀªÀiÁ£ÀªÁV GjAiÀÄÄvÀz Û .É Observation: Bubbles are quickly formed after adding lead oxide. A burning splinter held in the boiling tube in which the reaction is taking place burns brighter. PÁgÀt: «¨sÀd£ÉAiÀÄ GvÀà£ÀßUÀ¼ÃÉ £ÉÆgÀA É iÀiÁV §gÀÄwÛgÀÄvÀÛª.É CzÀg° À è MAzÁzÀ DQìd£ï zÀº£ À À QæAiÉÄAiÀÄ GvÉÃÛ dPÀ. Reason: The bubbles are the products of decomposition. The splinter burns brightly because one of the products, oxygen, is a supporter of combustion. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: PÁå¯ÉìöÊmï ºÀg½ À £À¯ÁèUÀĪÀ QæAiÉÄAiÀÄ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¢éªQÀ æèsª À À£ À ¥ÀæAiÉÆÃUÀ: ¥ÁgÀz± À ð À PÀ PÁå¯ÉìöÊmï ºÀgÀ¼£ À ÀÄß ¤«ÄµÀPÉÌ 5 ¨Áj DªÀwð¸ÀĪÀ ªÉÆÃmÁgï£À ªÉÄÃ¯É PÀÆj¸À¯ÁVzÉ. EzÀ£ÀÄß UÁf£À ªÀÄÄA¨sÁUÀªÀżÀî ¥ÉnÖUA É iÀÄ°è Ej¹zÉ. ¥ÉnÖUA É iÉƼÀPÉÌ ¸Àé®à ºÉÆUÉ vÀÄA©¹, CzÀ£ÀÄß ªÀÄÄaÑ ©r, §¢AiÉÆAzÀg° À è PÉÆgÉ¢gÀĪÀ ¸ÀtÚ gÀAzsÀæzÀ ªÀÄÆ®PÀ ºÀg½ À £À ªÉÄÃ¯É ¯ÉøÀgï ¨É¼PÀ £ À ÀÄß ºÁ¬Ä¹. «ÃQë¹: ºÀg½ À £À ªÉÄÃ¯É ©Ã¼ÀÄwÛgÀĪÀÅzÀÄ MAzÉà ¯ÉøÀgï QgÀtªÁzÀgÀÆ ºÀg½ À ¤AzÀ ºÉÆgÀ§gÀĪÀÅzÀÄ JgÀqÀÄ QgÀtUÀ¼ÀÄ. ºÀg¼ À £ À ÀÄß DªÀwð¹zÀgÉ MAzÀÄ QgÀtzÀ ¢PÀÄÌ §zÀ¯ÁUÀĪÀÅ¢®è, DzÀgÉ ªÀÄvÉÆÛAzÀgz À ÀÄ §zÀ¯ÁUÀÄvÀÛz.É PÁgÀt: PÁå¯ÉìöÊmï ºÀg½ À £À°è ¨ÉÃgÉ ¨ÉÃgÉ ¢PÀÄÌU¼ À ° À è ¨É¼QÀ £À ªÉÃUÀªÀÅ ¨ÉÃgÉ ¨ÉÃgÉAiÀiÁUÀĪÀAvÀºÀ gÀZ£ À É EzÉ. JAzÀgÉ ¨ÉÃgÉ ¨ÉÃgÉ ¢QÌ£À°è CzÀgÀ ªÀQæèsª À £ À ÁAPÀ ¨ÉÃgÉ ¨ÉÃgÉ EgÀÄvÀÛzÉ. ¢PÀÄÌ §zÀ°¸ÀzÀ QgÀtªÀ£ÀÄß ¸ÁªÀiÁ£Àå QgÀtªÉAzÀÆ ¢PÀÄÌ §zÀ°¸ÀĪÀ QgÀtªÀ£ÀÄß C¸ÁªÀiÁ£Àå QgÀtªÉAzÀÆ PÀgA É iÀÄÄvÉÛêÉ. Objective: To demonstrate birefringence or Double Refraction in Calcite Crystal Experiment: A transparent crystal of calcite is mounted on a 5 rpm motor. This is placed in a wooden box with a glass front. The box is closed and filled with a small quantity of smoke that enables us to see the path of light. A narrow beam of light from a laser pointer is shone on the crystal through an small opening in the box. Observation: A single beam of light enters the crystal but two beams emerge out of it. One of the beams has a fixed direction as the crystal rotates about a vertical axis. The other beam, however, rotates along with the crystal. Reason: Calcite has a structure that affects the speed of light differently along different directions – that is, different refractive indices. The beam that remains fixed in direction is called the Ordinary Ray and the other 'Extraordinary Ray'. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: JgÀqÀÄ ªÁºÀPU À ¼ À ° À è ¥ÀæªÀ»¸ÀĪÀ «zÀÄåvï MAzÉà ¢QÌ£À°èzÀÝg,É GAmÁUÀĪÀ ¥ÀjuÁªÀĪÀ£ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. Objective: To demonstrate the effect of parallel currents in conductors. ¥ÀæAiÉÆÃUÀ: 20£Éà UÉÃeï ¸ÀASÉåAiÀÄ vÁªÀÄæzÀ vÀAw¬ÄAzÀ 2000 ¸ÀÄwÛ£À ¸ÀÄgÀĽAiÀÄ£ÀÄß ªÀiÁrPÉƽî. ¸ÀÄgÀĽAiÀĵÉÖà JvÀÛg« À gÀĪÀ ±ÀÄzÀÞ PÀ©âtzÀ ¸ÀtÚ ¸À¯ÁPÉU¼ À £ À ÀÄß ¸ÀÄgÀĽAiÀÄ PÉÃAzÀæPÉÌ vÀÆj¹. ¸ÀÄgÀĽVAvÀ 2 ¸É.«ÄÃ. JvÀÛgz À ° À ègÀĪÀAvÉ vÁªÀÄæzÀ vÀmÉÖAiÀÄ£ÀÄß wgÀÄUÀ®Ä ¸ÁzsÀåªÁUÀĪÀAvÉ vÀÆV©r. EªÉgÀqg À À £ÀqÀÄªÉ Czsð À zÀªÀgU É ÀÆ E£ÉÆßAzÀÄ vÀmÉÖAiÀÄ£ÀÄß vÀÆj¹. ¸ÀÄgÀĽAiÀÄ£ÀÄß 220V J.¹. ªÉÄÊ£ïì£ÉÆA¢UÉ ¸ÀA¥ÀQð¹. Experiment: Make a 2000-turn #20 copper wire coil. Use thin, soft iron rods as the core. Let the core not extend beyond the height of the coil. Suspend a copper disc right above the coil separated by about 2 cm so that it is free to rotate. Now insert half way, a copper plate in the gap and connect the coil to 220V AC supply. «ÃQë¹: vÀÆV©lÖ vÀmÉÖ DªÀwð¸ÀÄvÀÛz.É Observation: The suspended disc rotates. PÁgÀt: ¸ÀÄgÀĽAiÀÄ°è ¥ÀæªÀ»¸ÀÄwÛgª À À J¹ «zÀÄåvï JgÀqÀÆ vÀmÉÖU¼ À ® À Æè §zÀ¯ÁUÀÄwÛgÀĪÀ «zÀÄåvï C£ÀÄß ¥ÉæÃgÉæ¸ÀÄvÀÛz.É EzÀjAzÁV GAmÁUÀĪÀ ¨sÁæªÀÄPÀ(torque)¢AzÀ vÀÆV©lÖ vÀmÉÖ DªÀwð¸ÀÄvÀÛz.É Reason: Alternating current in the coil induces a changing currents in the copper plate and the disc. This gives rise to a torque on the suspended disc that rotates it. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: PÉÆäÃAiÀÄ ¸ÀAªÉÃUÀzÀ ¤gÀƦ¸ÀĪÀÅzÀÄ. ¸ÀAgÀPÀëuA É iÀÄ£ÀÄß ¥ÀæAiÉÆÃUÀ: PÉÃAzÀæzÀ°è ¸À¯ÁPɬÄgÀĪÀ ¸ÉÊPÀ¯ï ZÀPÀæ CxÀªÁ wgÀÄUÀ§®è AiÀiÁªÀÅzÉà ZÀPÀæ – EzÀĪÉà eÉÊgÉÆøÉÆÌÃ¥ï. wgÀÄUÀÄ PÀÄaðAiÀÄ ªÉÄÃ¯É PÀĽvÀÄ, ¸ÉÊPÀ¯ï ZÀPÀ檣 À ÄÀ ß avÀæz° À è vÉÆÃj¹gÀĪÀAvÉ JgÀqÀÆ PÉÊUÀ½AzÀ »rzÀÄ ªÉÃUÀªÁV wgÀÄV¹. FUÀ ZÀPÀ檣 À ÀÄß MAzÀÄ PÀqU É É ªÁ°¹zÀg,É PÀÄaðAiÀÄÄ «gÀÄzÀÞ ¢QÌUÉ wgÀÄUÀÄvÀÛz.É PÁgÀt: DgÀA¨sz À ° À è ZÀPÀæ, ¤ÃªÀÅ ªÀÄvÀÄÛ PÀÄað J®èzj À AzÁV §gÀĪÀ ¤ªÀé¼À PÉÆäÃAiÀÄ ¸ÀAªÉÃUÀªÀÅ ±ÀÆ£ÀåªÁVgÀÄvÀÛz.É wgÀÄUÀÄwÛgÀĪÀ ZÀPÀ檣 À ÀÄß ªÁ°¹zÀgÉ PÉÆäÃAiÀÄ ¸ÀAªÉÃUÀªÀÅ §zÀ¯ÁUÀÄvÀÛz.É ºÁUÁV, PÀÄað «gÀÄzÀÞ ¢QÌ£À°è wgÀÄUÀĪÀ ªÀÄÆ®PÀ ¤ªÀé¼À PÉÆäÃAiÀÄ ¸ÀAªÉÃUÀªÀÅ ±ÀÆ£ÀåªÁUÀĪÀAvÉ ªÀiÁqÀÄvÀÛz.É Objective: To demonstrate conservation angular momentum Experiment: A bicycle wheel with axle forms what is known as a gyroscope – essentially a rotating wheel. Sit on the rotating chair and hold the axle of the bicycle wheel with two hands, as shown, and rotate the wheel as fast as you can. Now, slightly tilt the rotating wheel to one side, say, to your left. The chair rotates to your right. Reason: To start with, the rotating wheel, you and the chair have a total angular momentum equal to zero. By tilting the rotating wheel, the angular momentum changes. Consequently, the chair rotates in the opposite direction which will have an equal angular momentum in the opposite direction. Thus, the total angular momentum is still zero. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) zsÉåÃAiÀÄ: ªÉÄÃtzÀ §wÛ GjAiÀÄĪÀ°è CzÀgÀ D«AiÀÄ ¥ÁvÀ檣 À ÀÄß ¤gÀƦ¸ÀĪÀÅzÀÄ. ¥ÀæAiÉÆÃUÀ ÆÃUÀ: 10 ¸ÉA.«Äà X 10 ¸ÉA.«Äà C¼ÀvA É iÀÄ C®Æå«Ä¤AiÀÄA ºÁ¼ÉAiÀÄ°è ªÉÄÃtzÀ §wÛAiÀÄ°ègÀĪÀ §wÛAiÀÄ UÁvÀæPÉÌ vÀPÀÌ gÀAzsÀ檣 À ÀÄß ªÀiÁr. ªÉÄÃtzÀ §wÛAiÀÄÄ ¹Ügª À ÁV GjAiÀÄÄwÛgÀĪÁUÀ eÁé¯ÉAiÀÄÄ DgÀzA À vÉ eÉÆÃ¥Á£ÀªÁV §wÛAiÀÄÄ gÀAzsæz À À ªÀÄÆ®PÀ vÀÆgÀÀĪÀAvÉ ºÁ¼ÉAiÀÄ£ÀÄß Ej¹. «ÃQë¹: PÉ®ªÉà PÀëtUÀ¼° À è eÁé¯É £ÀA¢ºÉÆÃUÀÄvÀÛz.É PÁgÀt: ªÉÄÃtzÀ §wÛAiÀÄÄ GjAiÀÄÄwÛgÀĪÀAvÉ ¸Àé®à ¥ÀæªÀiÁtzÀ ªÉÄÃt PÀgV À §lÖ°£ÀAvÀºÀ gÀZ£ À A É iÀiÁUÀÄvÀÛzÉ zÀæªg À ÀÆ¥ÀzÀ ªÉÄÃt Pɦ®j §®¢AzÀ §wÛAiÀÄ ªÀÄÆ®PÀ ªÉÄïÉÃgÀÄvÀÛzÉ. §wÛAiÀÄ vÀÄ¢AiÀÄ°èAiÀÄ vÁ¥À¢AzÀ zÀæªg À ÀÆ¥ÀzÀ ªÉÄÃtªÀÅ D«AiÀiÁV vÀPÀëtªÉà ¸ÀÄ®¨sª À ÁV ºÉÆwÛPÉƼÀÄîvÀÛz.ÀÉ DzÀg,É C®Æå«ÄAiÀÄA ºÁ¼É GvÀÛªÀÄ ªÁºÀPª À ÁzÀÝjAzÀ ªÉÄÃt D«AiÀiÁUÀĪÀÅzÀPÉÌ CªÀPÁ±À«®èzA À vÉ vÁ¥Àª£ À ÀÄß »ÃjPÉƼÀÄîvÀÛzÉ. ºÁUÁV eÁé¯É £ÀA¢ºÉÆÃUÀÄvÀÛz.É Objective: To demonstrate the role of wax vapours in the burning of a candle. Experiment: Take a sheet of aluminium foil, say, 10 cm X 10 cm. Make a small hole at the centre of the foil – just big enough to slide through the wick of the candle. Light up the candle. When the flame is steady, carefully and gently insert the foil through the wick. Observation: The candle flame puts off in a few seconds Reason: The burning candle works by melting a little of the candle wax at the base of the wick. A cup-like structure holds the molten wax. This rises up the wick by capillary action. The heat at the tip vapourizes the wax which ignites easily. The aluminium foil conducts away heat even before wax vapours are formed. Hence, burning ceases. JAWAHARLAL NEHRU PLANETARIUM Science-in-Action (August 22-24, 2014) ¨ÉÃPÁUÀĪÀ ¸ÁªÀÄVæU¼ À ÀÄ: KtÄUÀ½gÀĪÀ PÉƼÀªÉ, ¤ÃgÀÄ, 2 §PÉmïUÀ¼ÀÄ (MAzÀÄ E£ÉÆßAzÀQÌAvÀ zÀÉÆqÀØzÁVgÀ¨ÉÃPÀÄ) «zsÁ£À: • aPÀÌ §PÉmï£À vÀ¼Àz° À è gÀAzsÀæ ªÀiÁr KtÄUÀ½gÀĪÀ PÉƼÀªA É iÀÄ£ÀÄß CzÀgÉƼÀUÉ vÀÆj¹. FUÀ F §PÉlÖ£ÀÄß ¤ÃjgÀĪÀ zÉÆqÀØ §PÉmï£À ªÉÄÃ¯É vÀ¯PÉ ¼ É U À ÁV Ej¹ PɼPÀ ÉÌ vÀ½îzÁUÀ ªÀÄvÀÄÛ ªÉÄîPÉÌ JwÛzÁUÀ £ÁzÀ ºÉƪÀÄÄävÀÛzÉ. • §PÉlÖ£ÀÄß ¤Ãj£ÉƼÀUÉ vÀ½îzÁUÀ, CzÀgÉƼÀVgÀĪÀ UÁ½AiÀÄ UÁvÀæ PÀrªÉÄAiÀiÁUÀÄvÀÛzÉ ªÀÄvÀÄÛ MvÀÛqÀ ºÉZÁÑUÀÄvÀÛzÉ. PÉƼÀªA É iÀÄ ºÉÆgÀ vÀÄ¢AiÀÄ §½ EgÀĪÀ MvÀÛqQÀ ÌAvÀ®Æ M¼À vÀÄ¢AiÀÄ §½ EgÀĪÀ MvÀÛqÀ ºÉZÁÑUÀÄvÀÛzÉ. ºÁUÁV UÁ½ M¼ÀvÀÄ¢¬ÄAzÀ ºÉÆgÀvÀÄ¢AiÉÄqÉUÉ zsÁ«¸ÀÄvÀÛz.É UÁ½AiÀÄ CtÄUÀ¼ÀÄ MAzÀPÉÆÌAzÀÄ C¥ÀླྀÀĪÀÅzÀjAzÀ GAmÁUÀĪÀ PÀA¥À£U À ¼ À ÀÄ ±À§Ý §gÀ®Ä ªÀÄÆ®PÁgÀt. • §PÉlÖ£ÀÄß ¤Ãj¤AzÀ ºÉÆgÀvU É A É iÀÄĪÁUÀ, §PÉnÖ£À M¼ÀUÉ MvÀÛqÀ PÀrªÉÄAiÀiÁUÀÄvÀÛz.É ºÉÆgÀvÀÄ¢¬ÄAzÀ M¼ÀvÀÄ¢AiÉÄqÉUÉ §gÀĪÀ UÁ½AiÀÄ CtÄUÀ½AzÁV ±À§Ý §gÀÄvÀz Û É. Apparatus Required: A corrugated tube, water, 2 buckets (one much larger than the other) Procedure: One end of a corrugated tube is fit properly into a hole made at the bottom of the smaller bucket. This is now kept inverted over a much larger bucket with water. We hear musical sounds as we press the small bucket into the water or pull it. As the inverted bucket is pressed down into the water, the volume for air molecules inside it is reduced. The pressure at the inner end of the tube is higher than that at the outer end. Therefore the air molecules inside the bucket rush to move out through the tube. They collide with each other setting up vibrations producing sound. When the bucket is pulled out, there is a low pressure inside the bucket. Now the air moving into it produces the sound.
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