Electrical engineering previous Year question ISRO | MCQ Question |Previous Years Questions

Electrical Engineering Questions MCQ Questions

Q1. A Meter has a full scale deflection of 90" at a current of 1A. The response of the meter is square law. Assuming spring control, the current for a deflection at 45" will be

(A) 0.25
(B) 0.50
(C) 0.707
(D) 0.67

Q2. A Single-phase Energy meter is operating on 230V, 50 Hz supply with a load of 20A for two hours at UPF. The meter makes 1380 revolutions in that period. The meter constant

(A) 695 rev/kWh
(B) 150 rev/kWh
(C) 0.15 rev/kWh
(D) 1/150 rev/kWh

Q3. In case of power measurements by two wattmeter method in a balanced 3-phase system

With pure inductive load

A) both wattmeters will indicates the same
(B) both wattmeters will indicate zero value but with opposite signs
(C)both the wattmeters will indicate the same value same sign
(D) one wattmeter will indicate zero and the other will indicate some non-Zero value

Q4. It is required to measure temperature in the range of 1300°C to 1500⁰C. The most suitable thermocouple to be used as transducer would be

(A)Chromel constantan
(B)lron-constantan
(C)Chromel - alumel
(D) Platinum-rhodiumn

Q5. Which dc motor will have highest percentage increase in input current for given percentage increase in torque

(A) Series motor
(B) shunt motor
(C) cumulatively compound motor
(D) separately excited motor

Q6. In a three phase delta transfomer, one phase burns up. The transformer will supply

(A) 57.7% of its rating
(B) zero output
(C) 63% of its output rating
(D) at full output rating

Q7. In an auto transtformer, power is transferred through

(A) conduction process alone
(B) induction process alone
(C) both conduction and induction
(D) mutual coupling processes

Q8. Buchholz relay is a

(A) voltage sensitive device
(B) current sensitive device
(C) frequency sensitive device
(D) gas actuated device

Q9. In Scott connection, if the ratio of the main transformer is k, then the teaser transformner has transformation ratio of

(A) 2k/N3
(B) 3k /2
(C)K/N3
(D) K/2

Q10. With core type transformers, the limbs are stepped so as to

(A) reduce the iron material and therefore iron loss
(B) provide better cooling
(C) reduce the conductor material and therefore I²R loss
(D) providee more mechanical strength to the core

Q11. In alternator, during hunting when the speed becomes super synchronous, the damper bars develop

(A) reluctance torque
(B) pseudo-stationary torque
(C) eddy current torque
(D) induction generator torque

Q12. It is never advisable to connect a stationary alternator to live bus-bar because it

(A) is likely to run as a synchronous motor

(B)will get short circuited
(C) will decrease bus-bar voltage though momentarily
(D) will disturbs generated emfs of other alternators connected in parallel

Q13. Under no load condition, the angle between the induced voltage and the supply voltage in synchronous motor is

(A) zero degree
(B) 45⁰
(C) 90⁰
(D) 180⁰

Q14. Synchronous motors are not self starting because

(A) Stator not used
(B) Starting winding not provided
(C) There is no slip
(D) The direction of instantaneous torque on the rotor reverses after half cycle

Q15. A three phase induction motor running at 1440 rpm on rated supply will run at the following rpm when fuse of one phase gets burnt