Ray Optics

which mirrors always produce virtual image?

• Plane mirror

• Concave mirror

• Convex mirror

• Both plane mirror and convex mirror

By which phenomenon light can propagate through an optical fiber?

• Reflection

• Internal reflection

• Total internal reflection

• Refraction

Refractive index of water is

In a convex mirror image is formed at centre of curvature when an object is placed

• At infinity

• in between focus and optical centre

• at centre of curvature

• in between centre of curvature and focus

The sparkle of a diamond can be explained by which phenomenon of

light ?

• Reflection

• Refraction

• Total internal reflection

• Diffraction

An optician prescribes a corrective lens of power + 2.5 D. What is the focal length of the lens?

• 40 m

• 40 cm

• 400 cm

• 4 m

An object is placed at the focus of a convex lens. Where will the image be formed?

• Centre of curvature

• Focus

• Infinity

• Between centre of curvature and focus

How magnification of simple microscope can be increased?

• Decreasing focal length of the lens

• Increasing focal length of the lens

• Increasing object distance

In a prism minimum deviation occurs when

• i=e

• i=r

• r=e