Module 3 important questions on Batteries
1. The cause of continuous foaming electrolyte in the Ni-Cd cell is:
a. excessive electrolyte
b. high rate of charging
c. contamination of cell due to foreign material like oil and grease
d. none of the above
2. For checking the voltage of battery before fitment in aircraft:
a. high discharge cell tester in used without load
b. high discharge cell tester is used with load
c. voltmeter is used
d. none of the above
3. The internal resistance of battery depends upon:
a. area of plates
b. resistance of electrolyte
c. distance between the plates
d. all the above
(Ref. TK Eismin, 49)
4. The amount of charge required (in ampere hour) to charge fully discharged battery:
a. 100% b. 140%
c. 160% d. 200%
(Ref. TK Eismin)
5. While carrying out capacity test on 24 battery, the circuit must be switched off when battery voltage drops to:
a. 18.2v b. 21.6v
c. 20.4v d. 21.4v
(Ref. TK Eismin, 45)
6. Thermal runaway in Ni-Cd battery is due to:
a. low internal resistance
b. high internal resistance
c. O2 combines with Cd at plate and generates real
d. as in (c) & it occurs when charging is done at constant current rate
(Ref. TK Eismin, 47)
7. A battery of 40AH capacity when charged by constant current method at 8 amps. Rate, charging time will be:
a. 5 hrs b. 6 hrs
c. 7 hrs d. 8 hrs
(Ref. TK Eismin)
8. In lead acid batteries spill proof vent plugs having heavy lend are used. Another type of plugs contain a sintered alumina (aluminum oxide) are used. The advantage of sintered alumina plug are:
a. permits diffusion of gases through it without letting fluids pass
b. it is much smaller and lighter
c. it save both space and weight
d. all the above
(Ref. TK Eismin, 38)