Question 511 Mark
Which colour of white light travels (a) fastest (b) slowest, in glass?
Answer
View full question & answer→Red colour travels fastest and Blue colour travels slowest in glass.
Questions · Page 2 of 2
[1 Mark Question Answer]
Question 521 Mark
How does the speed of light in glass change on increasing the wavelength of light?
Answer
View full question & answer→Speed of light increases with increase in the wavelength.
Question 531 Mark
How does the deviation produced by a triangular prism depend on the colours (or wavelengths) of light incident on it?
Answer
View full question & answer→The deviation caused by a prism increases with the decrease in the wavelength of light incident on it.
Question 541 Mark
what conclusion do you draw about the nature of white light in part (b)?
Answer
View full question & answer→We conclude that white light is polychromatic.
Question 551 Mark
If white light is used in same way as in part (a) above, what change is expected in the emergent beam?
Answer
View full question & answer→White light splits into its constituent colours i.e., spectrum is formed.
Question 561 Mark
If a monochromatic beam of light undergoes minimum deviation through an equiangular prism, how does the beam pass through the prism, with respect to its base?
Answer
View full question & answer→If a monochromatic beam of light undergoes minimum deviation through an equi-angular prism,
then the beam passes parallel to the base of prism.
then the beam passes parallel to the base of prism.
Question 571 Mark
In following diagram shows a thin beam of white light from a source S striking on one face of a prism.
What conclusion do you draw from the observation in part (b) above?
What conclusion do you draw from the observation in part (b) above?
Answer
View full question & answer→From the observation, we conclude that prism itself produces no colour.
Question 581 Mark
In following diagram shows a thin beam of white light from a source S striking on one face of a prism.
A slit is placed in between the prism and the screen to pass only the light of green colour. What will you then observe on the screen?
A slit is placed in between the prism and the screen to pass only the light of green colour. What will you then observe on the screen?
Answer
View full question & answer→When a slit is introduced in between the prism and screen to pass only the light of green colour, only green light is observed on the screen.
Question 591 Mark
What do you understand by the term spectrum?
Answer
View full question & answer→The colour band obtained on a screen on passing white light through a prism is called the spectrum.
Question 601 Mark
Define the term dispersion of light.
Answer
View full question & answer→The phenomenon of splitting of white light by a prism into its constituent colours is known as dispersion of light.
Question 611 Mark
The wavelengths for the light of red and blue colours are roughly $7.8 \times 10^7 m$ and $4.8 \times 10^7 m$ respectively.
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?
Answer
View full question & answer→(a) In vacuum, both have the same speeds.
(b) In a glass, red light has greater speed.
Question 621 Mark
Which colour of white light is deviated by a glass prism the most and which the least?
Answer
View full question & answer→A glass prism deviates the violet light most and the red light least.
Question 631 Mark
Name four colours of the spectrum of white light which have wavelength longer than blue light.
Answer
View full question & answer→Green, Yellow orange and red have wavelength longer than blue light.