Q .1. Give one useful and one
harmful effect of ultra violet radiation on the human
body.
body.
Q .2. Explain briefly how white
light gets dispersed by a prism.
Q .3. Name the extreme colours in a
pure spectrum of light.
Q .4. Name any four regions of
electromagnetic spectrum (other than visible light)
in increasing order of wavelength.
in increasing order of wavelength.
Q .5. Name any two electromagnetic
waves which have a frequency higher than that
of violet light. State one use of each.
of violet light. State one use of each.
Q
.6. Why are infrared radiations preferred over ordinary visible light for
taking
photograph in fog ?
photograph in fog ?
Q .7. A TV station transmits waves
of frequency 200 MHz. Calculate the wavelength of the waves if their
speed in air is 3.0 × 108 m s-1.
Q .8. a)State the equation for the
relation between frequency and wavelength of light in vacuum.
b)
How does the speed of light in glass change on increasing the wavelength of
light ?
light ?
