This set of Electric Drives Multiple Choice Questions & Answers (MCQs) focuses on “Solar Panels”.
1. A solar cell converts light energy into __________
a) Electrical energy
b) Thermal energy
c) Sound energy
d) Heat energy
View Answer
Explanation: A solar cell converts light energy into electrical energy. The light energy excites the electron of the solar cell which further flows in the circuit and constitutes the electric current.
2. There are three types of the solar cells.
a) True
b) False
View Answer
Explanation: There are three types of solar cells. Single crystal, polycrystal, and amorphous silicon cells are the major types of solar cells.
3. Series and parallel combination of the solar cell is known as _________
a) Solar array
b) Solar light
c) Solar sight
d) Solar eye
View Answer
Explanation: Series and parallel combination of the solar cell is known as Solar array. Shunt diodes are used to avoid the circulating current.
4. Full form of FF in the solar field is ____________
a) Form factor
b) Fill factor
c) Face factor
d) Fire factor
View Answer
Explanation: FF stands for Fill factor. It is the ratio of the maximum obtainable power to the product of the open-circuit voltage and short circuit current.
5. Calculate Fill factor using the data: Pmax=15 W, Voc=18 V, Isc=4 A.
a) .65
b) .59
c) .20
d) .98
View Answer
Explanation: 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)=15/72=.20.
6. Permanent magnet DC motor is more expensive than an Induction motor.
a) True
b) False
View Answer
Explanation: Permanent magnet DC motor is more expensive than an Induction motor because of the magnetic used in it. Magnets are made up of ferromagnetic material which results in high cost.
7. Calculate the line voltage in star connection when phase voltage=311 V.
a) 548.29 V
b) 538.66 V
c) 587.28 V
d) 185.58 V
View Answer
Explanation: The line voltage in case of star connection is 1.73 times of phase voltage. It leads the phase voltage by an angle of 30°. VL-L = 1.73×311 = 538.66 V.
8. The slope of the V-I curve of a solar cell is 66.1°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
a) 3.5 Ω
b) 2.2 Ω
c) 2.5 Ω
d) 2.9 Ω
View Answer
Explanation: The slope of the V-I curve of a solar cell is resistance. The slope given is 66.1° so R=tan(66.1°)=2.2 Ω. The slope of the I-V curve is reciprocal of resistance.
9. SCIM has a _________
a) Shorter life
b) Medium life
c) Longer life
d) Infinite life
View Answer
Explanation: SCIM stands for squirrel cage induction motor. It has high efficiency, maintenance-free operation, and long life because of rigidness nature.
10. The power factor of a SCIM generally is ___________
a) .1-.2
b) .6-.8
c) .3-.4
d) .5-.7
View Answer
Explanation: 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 SCIM generally is .6-.8.
11. Calculate the active power in a 11710 H inductor.
a) 8245 W
b) 1781 W
c) 0 W
d) 1964 W
View Answer
Explanation: 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 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
View Answer
Explanation: 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
View Answer
Explanation: 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
View Answer
Explanation: 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
View Answer
Explanation: 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.
Sanfoundry Global Education & Learning Series – Electric Drives.
To practice all areas of Electric Drives, here is complete set of 1000+ Multiple Choice Questions and Answers.
