Quiz: Electrical Engineering
Exam: UPSSSC JE
Each question carries 1 mark.
Negative marking: 1/4 mark
Time: 10 Minute
Q1. Most economical method for starting single-phase motor is?
(a) Induction-start method
(b) Split-phase method
(c) Capacitor start method
(d) Resistance-start method
Q2. For an 80% efficient transformer, the primary winding has 1000 turns and the secondary 100 turns. If the power input to the above transformer is 800 watts, the power output is __________.
(a) 1000 watts
(b) 640 watts
(c) 320 wats
(d) 10 kW
Q3. Voltmeter is a galvanometer with _____.
(a) high resistance
(b) low resistance
(c) both low and high resistance
(d) uncertain resistance
Q4. Transfer function of a system is This open-loop system is _________.
(c) marginally stable
(d) conditionally stable
Q5. A wire of resistance 0.1 Ω /cm is bent to form a square ABCD of side 10 cm. A similar wire is connected between B and D to form the diagonal BD. If a 2 V battery of negligible internal resistance is connected between A and C, then total power dissipated is
(a) 2 W
(b) 3 W
(c) 4 W
(d) 6 W
Q6. A cell supplies a current of 0.9 A though 2 Ω external resistance and 0.3 A through 7 Ω external resistance. The internal resistance of the cell is
(a) 0.5 Ω
(b) 1.2 Ω
(c) 1 Ω
(d) 1.5 Ω
Q7. If the capacitor of a single-phase motor is short circuited, the motor will __________.
(b) not start
(c) start with jerks
(d) start and then stop
Q8. The power measured by ammeter-Voltmeter method, if the voltmeter is connected across the load then the value of power will be
- The power consumed by the load
- The sum of power consumed by the load and the ammeter
- The sum of power consumed by the load and the voltmeter
- The sum of power consumed by the load, ammeter and voltmeter
Q9. For the same power the size of turbine
- Increase with speed
- Remains with speed
- Decrease with speed
- None of the above
Q10. Steam turbines are governed by
- Nozzle control governing
- Throttle governing
- Bypass governing
- All of the above
Capacitor start method is most economical method.
∵ Efficiency is 80 %
∴ Power output = .80×800 Wats =640 W
Here, two poles are at origin. So, system is unstable.
The given description forms a wheat stone bridge in balanced form.
∴ between A and C
∴ Total power = W
Lat internal resistance of call is r ohm.
0.9 (r+2) =0.3 (r+7)
Motor will not start.
The sum of power consumed by the load and the voltmeter
Decrease with the speed.
Mentioned all methods are used to govern steam turbine.