Physics Past Questions and Answers

In which of the following arrangements is the wavelength in an increasing order?

A Gamma rays, infra-red rays, x-rays, radiowaves
B Gamma rays, x-rays, infra-red ray, radiowaves
C Radiowaves, x-rays, gamma ray, infra-red rays
D Infra-red rays, radiowaves, x-rays, gamma rays

Question 397:

If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?

A Sin-1\(\frac{1}{2}\)
B Sin-1\(\frac{2}{3}\)
C Sin-1\(\frac{3}{4}\)
D Sin-1\(\frac{8}{9}\)

Question 398:

A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance, of 2.0cm from the tooth. The radius of Curvature of the mirror is

A 5.3cm
B 3.2cm
C 2.7cm
D 1.6cm

Question 399:

What is the effect of the increase in the size of the hole of a pin-hole camera on the image? it

A Gives a blurred image
B Corrects for chromatic aberration
C Magnifies the image
D Brings the image into a sharper focus

Question 400:

A pencil is placed vertically between a concave mirror and its focal point. The image of the pencil in the mirror will be

A Real, inverted and diminished
B Virtual, inverted and enlarged
C Real, erect and enlarged
D Virtual, erect and enlarged