NHPC-JE'21 EE: Daily Practices Quiz 09-NOV-2021

Table of Contents

NHPC JE Recruitment 2021

National Hydroelectric Power Corporation (NHPC) has released the recruitment notification for engagement of the following posts as Senior Medical Officer, Assistant Rajbhasha Officer, Junior Engineer & Sr. Accountant posts. NHPC expects applications from High Performing, Dynamic & Achievement-Oriented Professionals candidates to fill up these 173 vacancies.

NHPC-JE’21 EE: Daily Practices Quiz

NHPC-JE’21 EE: Daily Practices Quiz 09-NOV-2021

Each question carries 1 mark.
Negative marking: 1/4 mark
Total Questions: 06
Time: 06 min.

Q1. If a voltmeter is connected, like an ammeter, in series with the load,
(a) Almost no current will flow in the circuit
(b) The measurement reading will be too high
(c) The meter will burn out
(d) An inadmissibly high current will flow

Q2. The internal resistance of a milli-ammeter must be very low for
(a) High sensitivity
(b) High accuracy
(c) High precision
(d) minimum effect on the current in the circuit.

Q3. In which of the following motors is torque produced due to the tendency of the rotor to align itself in the minimum reluctance position when the speed of the motor is close to the synchronous speed?
(a) Hysteresis motor
(b) Repulsion motor
(c) Reluctance motor
(d) Universal motor

Q4. If A is the number of parallel paths and P is the number of poles, then the number of parallel paths in lap winding and in wave winding is
(a) A = P, A = 2
(b) A = 2P, A = P
(c) A = 2, A = P
(d)A = P, A = 2P

Q5. In a d.c. machine, the current rating and voltage rating of wave winding is
(a) Low, high
(b) High, low
(c) High, high
(d) Low, low

Q6. A forward bias PN junction will act as a/an:
(a) Amplifier
(b) Open switch
(c) Closed Switch
(d) Attenuator

SOLUTIONS

S1. Ans.(a)
Sol. Voltmeter has very high resistance to ensure that its connection do not alter flow of current in the circuit. Now if it is connected in series then no current will be there in the circuit due to its high resistance. Hence it is connected in parallel to the load across which potential difference is to be measured.

S2. Ans.(d)
Sol. A high value of internal resistance will vary the current considerably in a milli-ammeter as the current is in milli range. So, the internal resistance of a milli-ammeter must be very low.

S3. Ans.(c)
Sol. The reluctance motor has basically two main parts called stator and rotor. the stator has a laminated construction, made up of stampings. in the reluctance motor, rotor tries to align itself with the axis of rotating magnetic field in a minimum reluctance position. But due to rotor inertia, it is not possible, when rotor is in standstill condition.
So, rotor starts rotating near synchronous speed as a squirrel cage induction motor. When the rotor speed is about synchronous, stator magnetic field pulls rotor into synchronism i.e., minimum reluctance position and keeps it magnetically locked. Then rotor continues to rotate with a speed equal to synchronous speed. Such a torque exerted on the rotor is called the reluctance torque.

S4. Ans.(a)
Sol. number of parallel paths for LAP winding: A = P
Number of parallel paths for wave winding: A = 2

S5. Ans.(a)
Sol. wave winding is used for HIGH VOLTAGE and low current rating applications.

S6. Ans.(c)
Sol. If the positive terminal of an external battery is connected to p-type and its negative terminal to n-type of PN junction then such a biasing called forward biasing.
An ideal diode acts as a short circuit or closed switch under forward bias condition and open circuit or open switch under reverse biased condition.