21. Electric Vehicles are generally powered by __________
A. Aluminum batteries
B. Lead-acid batteries
C. Sodium batteries
D. Magnesium batteries
Answer: B
Electric vehicles are generally powered by Lead-acid batteries. They consist of lead electrodes with H2SO4 as an electrolyte.
22. Calculate the line voltage in star connection when phase voltage=315 V.
A. 545.5 V
B. 548.6 V
C. 547.8 V
D. 585.8 V
Answer: A
The line voltage in the case of star connection is 1.73 times of phase voltage. It leads the phase voltage by an angle of 30°.
VL-L=1.73×315=545.5 V.
23. Who coined the term battery?
A. George Franklin
B. Benjamin Fernandes
C. Benjamin Franklin
D. George Bush
Answer: C
Benjamin Franklin was the first who coined the term battery. Batteries were the main source of electrical energy before the invention of generators.
24. Who invented the battery?
A. Alessandro Volta
B. Alexander Bell
C. Alessandro Bell
D. Tim Southee
Answer: A
A battery converts chemical energy into electrical energy. Alessandro Volta invented the battery in 1800. He was an Italian scientist.
25. Combination of cells is known as the battery.
A. True
B. False
Answer: A
A battery is a combination of cells connected in parallel and series. It converts chemical energy into electrical energy.
26. Calculate the active power in a 315 F capacitor.
A. 45 W
B. 81 W
C. 0 W
D. 64 W
Answer: C
The capacitor 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 capacitor so the angle between V & I is 90°.
P = VIcos90° = 0 W.
27. Calculate the frequency of the waveform v(t) = sin(πt+π÷4) + sin(πt+π÷74) + sin(πt+π÷56).
A. .1 Hz
B. .8 Hz
C. .5 Hz
D. .2 Hz
Answer: C
The fundamental time period of the sine wave is 2π. The time period of i(t) is L.C.M {2,2,2}=2 sec.
The frequency of the waveform is 1/2=.5 Hz. The time period is independent of phase shifting and time-shifting.
28. The diode conducts only when current flows from anode to cathode.
A. True
B. False
Answer: A
A diode is a unidirectional device. It starts conduction when current flows from the cathode to the anode of the diode. It is a bipolar device.
29. Full form of EV is ____________
A. Energy voltage
B. Electric vehicles
C. Electric voltage
D. Energy vehicles
Answer: B
The full form of EV is Electric Vehicles. It uses an electric motor for the machine propulsion. It does not cause pollution as there is no tail-to-pipe emission.
30. Full form of ICV is ____________
A. Internal combustion vehicles
B. Internet combustion vehicles
C. Internally combined vehicles
D. Internet combined vehicles
Answer: B
The full form of ICV is an Internal combustion vehicle. It requires fuel for propulsion. It consists of a piston attached to a cylinder chamber.
