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 27-Oct-2021
Each question carries 1 mark.
Negative marking: 1/4 mark
Total Questions: 06
Time: 06 min.
Q1. Which of the following causes permanent damage to a transmission line insulator?
(a) Corona discharge
(c) Dry band arcing
Q2. Which of following relay is used for transformer protection?
(a) Mho relay
(b) Distance relay
(c) Impedance relay
(d) Buchholz relay
Q3. An amplifier has a voltage gain 60 and β = 100. The power gain of the amplifier is:
Q4. Which of the following yields high starting torque?
(a) DC shunt motor
(b) DC series motor
(c) Differential-compound motors
(d) Cumulative-compound motors
Q5. An amplifier has a voltage gain A_v=1000. The voltage gain in dB is:
(a) 3 dB
(b) 20 dB
(c) 30 dB
(d) 60 dB
Q6. Which gates are known as universal gates?
(a) NAND & NOR
(b) AND & NOT
(c) OR & NOT
(d) AND & OR
Sol. As puncture destroys the insulator, it is more serious than flash-over. Therefore, Safety Factor is defined for an Insulator. Safety factor of an Insulator is defined as the ration of Puncture Voltage to the Flash Over Voltage.
Safety Factor = Puncture Voltage / Flash Over Voltage
So, (Puncture Voltage)/ (Flash Over Voltage)>1.
Sol. Buchholz relay.
Sol. Power gain=β×voltage gain=100×60=6000.
Note: voltage gain=β×(R_out/R_in )
Sol. DC series motor.
Sol. Voltage gain in dB=20 log〖A_V=20 log〖1000=20 log〖10^3=3×20=60 dB.〗 〗 〗
Sol. NAND & NOR gates are universal gates.