Basic Electrical Engineering Questions

21-The maximum efficiency of transformer is obtained when:

(A) Copper loss is maximum

(B) Copper loss is equal to iron loss

(C) Iron loss is maximum

(D) Running without loss


22-Rawl plug tool and bit is used for

(A) Making holes in wood

(B) Making piolet holes in wood

(C) Making holes in metal sheets

(D) Making holes in bricks and concrete wall


23-The heat proof insulating material used for heater base is:

(A) Mica

(B) Porcelain

(C) Asbestos

(D) Glass wool


24-Buchhol’z relay is a device related with:

(A) Alternator

(B) Synchronous motor

(C) Auto transformer

(D) Transformer


25-The initial function of a choke in a tube light circuit is to:

(A) Limit the starting current

(B) Heat up the filament

(C) Provide high voltage initially

(D) Keep the voltage same


26-An electrical circuit that has infinite resistance shown in megger is called a ___ circuit.

(A) An open

(B) Short

(C) A ground

(D) Closed


27-Auto transformer works on the principle of

(A) Mutual induction

(B) Self induction

(C) Conduction

(D) Electron fusion


28-The formula for calculating power in R-L circuit is:

(A) V x I

(B) I2Z

(C) VICosθ

(D) VISinθ


29-When the disc of an energy meter is rotating even without connecting any load, the error is called?

(A) Creeping error

(B) Phase error

(C) Friction error

(D) Temperature error


30-Which insulator is used on dead ends of medium voltage line?

(A) Egg shape

(B) Pin type

(C) Shackle type

(D) Disc type


31-In purely capacitive AC circuit the:

(A) Current leads the voltage

(B) Voltage leads current

(C) Current and Voltage in phase

(D) Current lags current


32-Dynamo meter type instruments are used to measure:

(A) Only AC quantities

(B) Both AC and DC

(C) DC only

(D) AC only


33-MCCB stands for:

(A) Metal Close Circuit Breaker

(B) Main Current Circuit Breaker

(C) Moulded Case Circuit Breaker

(D) Miniature Current Circuit Breaker


34-The power factor of an AC circuit is given by:

(A) Cosine of the phase angle

(B) Tangent of the phase angle

(C) The ratio of R/X

(D) The ratio of XL/Z


35-The total opposition offered by an AC circuit is called:

(A) Inductive reactance

(B) Resistance

(C) Capacitive reactance

(D) Impedance



21-(B), 22-(D), 23-(A), 24-(D), 25-(C), 26-(A), 27-(A), 28-(C), 29-(A), 30-(D), 31-(A), 32-(B), 33-(C), 34-(A), 35-(D)