TEST SERIES - 66 (I)

When an ebonite rod is rubbed with fur, the charge acquired by the fur is

• Negative

• Positive

• Neutral

• None of the above

Which of the following pairs of material serves as electrodes in chargeable batteries commonly used in device such as torch?

• Iron and cadmium

• Nickel and cadmium

• Lead peroxide and lead

• Zinc and carbon

Conversion of chemical energy into electrical energy occurs in

• Atomic bombs

• Electric heaters

• Battery

• Dynamo

A thermoelectric refrigerator works on

• Joule effect

• Seebeck effect

• Peltier effect

• None of the above

In the electrolysis the amount of mass deposited or liberated at an electrode is directly proportional to

• Square of electric charge

• Amount of charge

• Square of current

• None of the above

The temperature at which thermoelectric power of a thermo couple becomes zero, is called

• Inversion temperature

• Neutral temperature

• Junction temperature

• Null temperature

The temperature at which a ferromagnetic material becomes paramagnetic, is called

• Critical temperature

• Inversion temperature

• Curie temperature

• Neutral temperature

The core of an electromagnet is made of soft iron because soft iron has

• Small susceptibility and small retentivity

• Large susceptibility and small retentivity

• Large density and large retentivity

• Small density and large retentivity

A source of magnetic field is

• A static electric charge

• A moving electric charge

• A current loop

• Both (b)and (c)

A magnetic needle is kept in nonuniform magnetic field. It exper

• A force and a torque

• A force but not a torque

• A torque but not a force

• None of the above