ICSE-X-Physics
Previous Year Paper year:2014
- #3-c-iA ray of light passes from water to air. How does the speed of light change?Ans : Light travels denser to rarer, speed of light increases.
- #3-c-ii [2]Which colour of light travels fastest in any medium except air?Ans : Red colour of light travels fastest in any medium except air.
- #3-d [2]Name the factors affecting the critical angle for the pair of media.Ans : Factors affecting the critical angle for the pair of media are :
(i.) Effect of colour and
(ii.) Effect of temperature.
- #3-e
- #3-e-iName a prism required for obtaining a spectrum of Ultraviolet light.Ans : Quartz prism.
- #3-e-ii [2]Name the radiations which can be detected by a thermopile.Ans : Infrared radiations can be detected by thermopile.
- #4
- #4-a [2]Why is the colour red used as a sign of danger?Ans : Since the wavelength of red colour is maximum in the visible light, the light of red colour is scattered least by the air molecules of the atmosphere and therefore it can reach to a longer distance.
- #4-b
- #4-b-iWhat are mechanical waves?Ans : The sound waves require a medium for their propagation. These waves travel in the medium though the vibrations of the medium particles about their mean positions, so they are also called elastic or mechanical waves.
- #4-b-ii [2]Name one property of waves that do not change when the wave passes from
one medium to another.Ans : Frequency.
- #4-c [2]Find the equivalent resistance between points A and B
Ans :
- #4-d [2]``\pu{50 g }`` of metal piece at ``\pu{27°C }`` requires ``\pu{2400 J }`` of heat energy so as to attain a
temperature of ``\pu{ 327 °C }`` . Calculate the specific heat capacity of the metal.Ans :
- #4-e [2]An electron emitter must have _____________ work function and ___________ melting
point.Ans : An electron emitter must have low work function and high melting point.
- # [40]Section : IIAttempt any four questions from this Section