When maximum power transfer takes place, the efficiency of power transfer of the circuit is 

(A) 100% 

(B) 75% 

(C) 50% 

(D) 25%

An ideal voltage source should have: 

(A) Zero source resistance 

(B) Infinite source resistance 

(C) Terminal voltage is proportional to current 

(D) Open-circuit voltage nearly equal to voltage of the load current

The superposition theorem requires as many circuits to be solved as there are: 

(A) Nodes 

(B) Sources 

(C) Nodes and Sources 

(D) Nodes, Sources and Mesh

A wire of resistance R has it length and cross-section both doubled. Its resistance will become 

(A) 4 R 

(B) 2 R 

(C) R 

(D) R / 4.

Which of the following is not the same as watt?

(A) joule/sec 

(B) amperes/volt 

(C) amperes x volts 

(D) ( amperes )² x ohm.

Ohm’s law is not applicable to

(A) DC circuits 

(B) high currents 

(C) small resistors 

(D) semi-conductors.

Transformer is a device which 

(A) Work through on electric induction. 

(B) Can step up or step down the level of voltage. 

(C) All of these 

(D) Its Working without changing the Power.

In alternator frequency f= 

(A) NP/120 

(B) NP120 

(C) N/120P 

(D) 1/NP120 

Transfer of electrical power from primary to secondary in a transformer takes place 

(A) Electrically 

(B) Magnetically 

(C) None of these 

(D) Electromagnetically

 If a sinusoidal exciting current is applied to a transformer, the mutual flux produced is

(A) Zero 

(B) Sinusoidal 

(C) Flat top 

(D) Negative