Light

Power of the lens is -40D, its focal length is :-

• 4m

• -40m

• -0.025m

• 25m

In optics, an object which has higher Refractive Index is called :-

• Optically rarer

• Optically Denser

• Refractive Index

• Optical Index

The optical phenomena, twinkling of starss, is due to

Convex lens focuses a real, point-sized image at the focus. The object is placed :

• At focus

• Between F & 2F

• At infinity

• At 2F

The magnification produced by a plane mirroris +1. What does this mean ?

Which of the following can make a beam of light parallel when light from a point source is incident on it ?

• Two plane mirrors placed parallel to each other

• Convex Mirror as well as concave lens

• Concave mirror as well as convex lens

• Concave mirror as well as concave lens