Q.51)-What is a zoom lens?
- A lens with a definite focal length
- A lens with a transitional focal length
- It is used in radio telescopes
- None of these
Q.52)-Dioptre is the unit of
- Power of lens
- Focal length of lens
- Intensity of lens
- Intensity of sound
Q.53)-Radio telescope are better than optical telescopes because
- They can detect faint galaxies which cannot be done by optical telescope
- They can even work in cloudy conditions
- They can work during day and night
- All of the above
Q.54)-To eliminate the glare of headlight in motorcars
- Polaroid's are used
- Glass prism are used
- Thin films are used
- Filters are used.
Q.55)-The outer white part of the eye that protects the inner structure is
- Iris
- Sclera
- Retina
- Cornea
Q.56)-Person who is color blind can not distinguish between
- Black and yellow
- Red and green
- Yellow and white
- Green and blue
Q.57)-The least distance of distinct vision is
- 35 cm
- 25 cm
- 45 cm
- 15 cm
Q.58)-Distant objects are visible as little out of focus in the condition
- Presbyopia
- Hpermetropia
- Astigmatism
- Myopia
Q.59)-Sensitivity of human eye is maximum in the
- Violet region
- Green region
- Blue region
- Red region
Q.60)-A man can not see clearly beyond 10 meters. The disease he suffers from.
- Far sight
- Myopia
- Cataract
- Hypermetropia