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

 

ANSWERS:

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)