set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

An object is placed at the focus of a concave mirror. The image will be

a) virtual, inverted, highly enlarged at infinity

b) real, inverted, same size at the focus

c) real, upright, same size at the focus

d) real, inverted, highly enlarged at infinity

Question : 2

Of the two bulbs in a house, one glows brighter than the other. In this context which of the following statements is correct?

a) The bright bulb has larger resistance

b) The brightness does not depend on the resistance

c) Both the bulbs have same the resistance

d) The dim bulb has larger resistance

Question : 3

In a semiconductor, the concentration of electrons is 8 × 10¹⁴/cm³ and that of the holes is 5 × 10¹² cm³ . The semiconductor is

a) n-type

b) intrinsic

c) p-type

d) Cannot say

Question : 4

When a p-n junction diode is reverse biased the flow of current across the junction is mainly due to

a) drift of charges

b) depends on the nature of material

c) diffusion of charges

d) both drift and diffusion of charges

Question : 5

Lenz’s law is a consequence of the law of conservation of

a) mass

b) energy

c) charge

d) momentum

Question : 6

The laws of electromagnetic induction have been used in the construction of a

a) voltmeter

b) electric motor

c) galvanometer

d) generator