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 19-Oct-2021
Each question carries 1 mark.
Negative marking: 1/4 mark
Total Questions: 06
Time: 06 min.
Q1. Pelton wheels are most efficient under the conditions of……….
(a) High pressure and high flow
(b) Low pressure and low flow
(c) Low pressure and high flow
(d) High pressure and low flow
Q2. In a power station,
(a) Reserve capacity = Plant capacity + Max. demand
(b) Reserve capacity = Plant capacity – Average demand
(c) Reserve capacity = Plant capacity – Max. demand
(d) Reserve capacity = Plant capacity + Average demand
Q3. In a 3-phase system, the line losses are
(a) directly proportional to cos ϕ
(b) inversely proportional to cos ϕ
(c) inversely proportional to cos² ϕ
(d) none of the above
Q4. The breaking capacity of a 3-phase circuit breaker is given by
(a) √3 × service voltage × rated symmetrical current
(b) 3 × service voltage × rated symmetrical current
(c) 2 × service voltage × rated symmetrical current
(d) None of the above
Q5. Tellegen’s theorem is based on the principle of law of _________________.
(a) Conservation of charge
(b) Conservation of mass
(c) Conservation of velocity
(d) conservation of energy
Q6. A D.C. Generator has 6 poles, A brush shift of 6° actual means a brush shift of
(a) 6° electrical
(b) 18° electrical
(c) 30° electrical
(d) 2° electrical
Sol. Pelton wheels are suitable for low discharge and high head(pressure)
Pelton wheel is an example of impulse turbine.
Sol. Reserve capacity = Plant capacity – Max. demand
Sol. Line current, IL=P/(√3 VL cosϕ )
Since line losses are proportional to the square of IL, it follows that line losses are proportional to 1/cos² ϕ.
Sol. It is current (rms) that a circuit breaker is capable of breaking at given recovery voltage and under specified conditions.
Breaking capacity = √3 × service voltage × rated symmetrical current
Sol. (θele= P/2×θmech )
= 18° electrical