11. Calculate the active power in a 11710 H inductor.
A. 8245 W
B. 1781 W
C. 0 W
D. 1964 W
Answer: C
The inductor is a linear element. It only absorbs reactive power and stores it in the form of oscillating energy. The voltage and current are 90° in phase in the case of the inductor so the angle between V & I is 90°.
P = VIcos90° = 0 W.
12. Calculate the frequency of the waveform i(t) = sin(πt+π÷4)+sin(πt+π÷74).
A. .5 Hz
B. .8 Hz
C. .1 Hz
D. .9 Hz
Answer: A
The fundamental time period of the sine wave is 2π.
The time period of i(t) is L.C.M {2,2}=2 sec.
The frequency of the waveform is 1/2 = .5 Hz. The time period is independent of phase shifting and time-shifting.
13. Full form of CEL is ____________
A. Central Electronics Limited
B. Central Electrical Limited
C. Circle Electronics Limited
D. Circle Electrical Limited
Answer: A
The full form of CEL is Central Electronics Limited. It is a Government of India enterprise founded in 1974. It is a publicly listed company.
14. Full form of BEL is ____________
A. Busy Electronics Limited
B. Burden Electrical Limited
C. Bharat Electronics Limited
D. Brahma Electrical Limited
Answer: C
The full form of BEL is Bharat Electronics Limited. It is a Government of India enterprise founded in 1954. It is a publicly listed company.
15. Material used for making solar cell is _________
A. Silicon
B. Carbon
C. Sodium
D. Magnesium
Answer: A
The material used for making solar cells is Silicon. It is a naturally obtained semi-conductor. It has a lower cut-off voltage and minimum energy bandgap.
16. The output power of the centrifugal pump is proportional to the _________ of the speed.
A. Square
B. Cube
C. Square-root
D. Cube-root
Answer: B
The output power of the centrifugal pump is proportional to the cube of the speed. They require a small torque to start.
17. There are four types of Water pumps.
A. True
B. False
Answer: B
There are two types of Water pumps. Centrifugal and reciprocating are the major types of water pumps.
18. The output of the Solar panel is DC.
A. True
B. False
Answer: A
The output of the solar panel is DC. Inverters are used at the output terminals of the solar panel in order to convert DC into AC.
19. Which of the relationship is correct in a Permanent magnet DC motor?
A. T ∝ (Ia)2
B. T ∝ (Ia)0
C. T ∝ Ia
D. T2 ∝ Ia
Answer: C
The value of flux remains constant in the Permanent magnet DC motor. The torque in the PMMC motor is directly proportional to the armature current.
20. Calculate the Fill factor using the data: Pmax=5 W, Voc=5 V, Isc=1 A.
A. 5
B. 3
C. 2
D. 1
Answer: D
The fill factor is the ratio of the maximum obtainable power to the product of the open-circuit voltage and short circuit current.
F.F=Pmax÷(Voc×Isc)=5/5=1.
21. Full form of ICE is ____________
A. Internal Combustion Engine
B. International Combustion Engine
C. Iterative Combustion Engine
D. Iterative Commercial Engine
Answer: A
The full form of ICE is International Combustion Engine. It consists of pistons inside the closed chamber in order to drive the machine.
22. Which of the relationship is correct in a Permanent magnet DC motor?
A. E ∝ (N)2
B. E ∝ (N)0
C. E ∝ N
D. E2 ∝ N
Answer: C
The value of flux remains constant in the Permanent magnet DC motor. The back e.m.f in the PMMC motor is directly proportional to the speed.
23. Full form of SSS is ____________
A. Saur Sujala Yojana
B. Saur Solar Yojana
C. Solar Sun Yojana
D. Sun Sujala Yojana
Answer: A
Full form of SSS is Saur Sujala Yojana. It is an initiative by the Government of India to encourage people to use solar energy as an energy source.
24. Who made the first solar cell?
A. Gerald Pearson
B. Tim Bell
C. Tim Cook
D. Nicola Tesla
Answer: A
The first solar cell was made by Gerald Pearson in 1954 in Bell laboratories. It was a lithium-silicon photovoltaic cell.
25. When was the first solar cell invented?
A. 1950
B. 1954
C. 1965
D. 1952
Answer: B
The first solar cell was made by Gerald Pearson in 1954 in Bell laboratories. It was a lithium-silicon photovoltaic cell.
26. Who invented the first Solar car?
A. Ian Bell
B. Trent Boult
C. Jon Woakes
D. William G. Cobb
Answer: D
The first solar car was invented by William G. Cobb in 1955. It was a 15-inch vehicle. It was made by General Motors.
27. The power factor of a WRIM generally is ___________
A. .1-.2
B. .6-.8
C. .3-.4
D. .5-.7
Answer: D
At light loads, the current drawn is largely a magnetizing current due to the air gap and hence the power factor is low. The power factor of a WRIM generally is .5-.7.
28. Full form of BHEL is ____________
A. Bharat Heavy Electronics Limited
B. Bharat Heavy Electrical Limited
C. Bharat Hero Electronics Limited
D. Busy Hero Electrical Limited
Answer: B
The full form of BHEL is Bharat Heavy Electrical Limited. It is a Government of India enterprise founded in 1964. It is a publicly listed company.
29. Calculate peak-peak voltage if Vmax=0 V and Vmin=9 V.
A. -5 V
B. -6 V
C. -9 V
D. -10 V
Answer: C
Peak-Peak voltage is equal to the difference between the maximum and minimum voltage. It is mathematically represented as
Vp-p=Vmax-Vmin=0-9=-9 V.
30. Calculate the De-rating factor if the string efficiency is 5 %.
A. .95
B. .55
C. .65
D. .85
Answer: A
The de-rating factor is used to measure the reliability of a string. The value of the De-rating factor is 1-(string efficiency)=1-.05=.95.
