Which of the following functions is performed by a photo cell?

1. 1. It converts magnetic energy into electrical energy
   2. It converts chemical energy into electrical energy
   3. It converts electrical energy into light energy
   4. It converts light energy into electrical energy

An electric motor runs on which principle?

1. 1. The current flowing through a conductor causes generation of heat that drives the engine
   2. Changing magnetic field induces an electromotive force in a conductor
   3. A conductor carrying current n the direction perpendicular to the external magnetic field feels a force
   4. Electrical energy can be converted into chemical energy in the presence of magnetic fields

Ball bearings are used to reduce frictions by_____.

1. 1. Reducing the area of contact with the use of metallic balls
   2. Applying lubricants to the balls used
   3. Increasing the area of contact with the use of metallic balls
   4. None of the above

Which one of the following is not an advantage of three phase system of electric power supply over one phase system?

1. 1. The power consumption is less
   2. the output voltage is higher
   3. The total output is almost constant
   4. the output of a 3-phase machine is greater than that of a single phase machine

Permanent magnets are made from _____.

1. 1. Dielectric substances
   2. Diamagnetic substances
   3. Paramagnetic substances
   4. Ferromagnetic substances

Coper wires are generally used for electrical power transmission instead of iron wires because _____.

1. 1. Copper is cheaper than iron
   2. Copper is a better conductor than iron
   3. Copper is lighter than iron
   4. Copper can take higher power than iron

Which of the following instruments may be use to measure A.C?

1. 1. Hot-wire ammeter
   2. Moving coil galvanometer
   3. Galvanometer
   4. None of these

Which one of the following is not an advantage of AC over DC?

1. 1. In AC the magnitude of current can be reduced by a choke
   2. In AC a wide range of voltage s is possible
   3. Lines loss in AC transmission lines are negligible
   4. The AC sows skin effect

A car is running on a road at a uniform speed of 60 km/hr. The net resultant force on the car is_____.

1. 1. Equal to zero
   2. Driving force in the direction of car’s motion
   3. An inclined force
   4. resistance force opposite to the direction of car’s motion

The two parallel wires carrying current in the opposite direction _____.

1. 1. Do not exert any force on each other
   2. Repeal each other
   3. Attract each other
   4. None of these