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

Question : 1 [IAS Prelim]

Fluorescent tubes are fitted with a choke. The choke coil :

a) reduces current in the circuit

b) steps up the line voltage

c) steps-down the line voltage

d) chokes low frequency current

Question : 2

In semiconductors, at room temperature

a) the valence band is partially empty and the conduction band is partially filled

b) the valence band is completely filled and the conduction band is partially filled

c) the conduction band is completely empty

d) the valence band is completely filled

Question : 3 [PCS (Pre) 2016]

Nickel-Cadmium (Ni-Cd) battery is used in

a) Transistors

b) Calculator

c) Cordless electronic appliances

d) All of the above

Question : 4

Zener breakdown takes place if

a) doped impurity is high

b) less impurity in n-part

c) doped impurity is low

d) less impurity in p-part

Question : 5

When n-type semiconductor is heated

a) number of holes increases while that of electrons decreases

b) number of electrons and holes remain same

c) number of electrons increases while that of holes decreases

d) number of electrons and holes increases equally