5. Electrical Question & Answer (Points) for Tests / Interview

Ø  A moving coil voltmeters measures only DC voltages.

Ø  Bench charge is given to the battery when taken off the vehicle.

Ø  Damping force acts on the moving system of an indicating instrument only when it is moving.

Ø  During the charging and discharging of a nickel iron cell water is neither formed nor absorbed.

Ø  Eddy current is the most efficient form of damping employed in electrical instruments.

Ø  Floating battery systems are widely used for power stations, emergency lighting and telephone exchange installations.

Ø  kWh meter can be classified as recording instrument.

Ø  Moving iron instruments can be used for measuring direct currents and voltages and alternating current and voltages.

Ø  One complete set of positive and negative values of alternating quantity is known as one cycle.

Ø  Permanent magnet moving coil ammeter have uniform scales because they are spring-controlled and their deflecting torque varies directly as current.

Ø  Permanent magnet type meter is suitable for only direct current measurements.

Ø  Sediment accumulates at the bottom of a lead-acid battery consists largely of antimony-lead alloy.

Ø  The efficiency of a nickel-iron cell is less due to its higher internal resistance.

Ø  The hot-wire ammeter reads equally well on DC and / or AC circuits.

Ø  The moving system of an indicating type of electrical instrument is depending upon a deflecting torque, controlling torque and damping torque.

Ø  The reduction of battery capacity at high rates of discharge is primarily due to the rapid formation of lead sulphate on the cell plates.