7000+ GATE ECE Previous Year Question Papers Pdf - 1

Question: 1

During short circuit test of a transformer, core losses are negligible because

(A) Full load current is not supplied to the transformer

(B) The voltage applied on the primary side is low

(C) The voltage on the secondary side is zero

(D) The current on the secondary side is rated current

Question: 2

When a transformer is operating on no load, the primary applied voltage is approximately balanced by

(A) Voltage drop across the resistance and reactance

(B) Terminal voltage across the secondary

(C) Primary induced emf

(D) Secondary induced emf

Question: 3

Power transformers are designed to have maximum efficiency around _____ full load.

(A) 25% of

(B) 50% of

(C) 75% of

(D) Nearly

Question: 4

In a dc motor, the shaft torque is less than armature torque. This is due to

(A) Stray loss

(B) Eddy current loss

(C) Hysteresis loss

(D) All of the above

Question: 5

A transformer transforms

(A) Voltage and current

(B) Frequency

(C) Current

(D) Voltage