Physics Past Questions and Answers

When an object is placed between the principal focus and the optical center of a convex lens, it could be used as a?

A Simple microscope
B Refecting lens
C Compound microscope
D Projector

Question 22:

The production of pure spectrum could easily be achieved using a?

A Glass prism with a pin
B Triangular prism with two convex lens
C Traingular prism only
D Triangular prism with two concave lenses

Question 23:

A charge 50 µc has electric field strength of 360 NC-1 at a certain point. The electric field strength due to another charge 120 µc kept at the same distance apart and in the same medium is?

A 864 NC^-1
B 150 NC^-1
C 144 NC^-1
D 18 NC^-1

Question 24:

The energy E of a photon and it's wavelength are related by EÎ» = X. the numerical value of X is?
[h = 6.63 x 10^-34js, c = 3 x 10⁸ ms^-1]

A 6.6 X 10^-28
B 1.99 X 10^-27
C 6.60 x 10^-26
D 1.99 x 10^-25

Question 25:

The bond that forms a semiconductor is?

A Covalent
B Electrovalent
C Ionic
D Metallic