electric current and magnetism - Category wise Question and Answer Practice Test with Solutions

Question : 26 [NDA]

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 : 27 [UPPCS (Pre) 2009]

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 : 28

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 : 29 [RAS/RTS (Pre) 1998]

Fuse wire used for safety of household have

a) High resistance

b) Low melting point

c) High melting point

d) Both (a) and (b)

Question : 30

Consider the following statements :

1. The magnetic pole in the northern hemisphere is the north magnetic pole.
2. At all points on a magnet, an iron bar gets attracted.

a) 1 and 2 both

b) 1 only

c) 2 only

d) None