Important Physics MCQ for Railway NTPC Exam
Important Physics MCQ for Railway NTPC Exam
1. Capacitor mainly used in DC circuit as
a.Rectifier
b. As filters
c. As stabilizer
d. B and C
Ans – d. B and C
2.In one time constant capacitor takes the charge up to __________%of its full value:-
a.36%
b. 26%
c. 63.2%
d. 80.2%
Ans -c. 63.2%
3.Effective value of a sine wave current is nearly
a. √2 X I max
b. I max X 1/√2
c. 0.637X I max
d. None
Ans -b. I max X 1/√2
4. What is the power factor of a parallel resonance circuit:-
a. Unity
b. Zero
c..5
d. .866
Ans -a. Unity
5. The unit of resistivity is :-
a. Ohm-meter
b. ohm/meter
c. Ohm-centimeter
d. Ohm/sq cm
Ans- a. Ohm-meter
6. A circuit breaker that can not be reset when the circuit fault exist is called:-
a. Electrical CB
b. Non resettable CB
c. Trip free CB
d. Polarized CB
Ans- c. Trip free CB
7. With rise temperature the change in resistance in Eureka(High resistance alloy) is:-
a. Very high
b. Very less
c. Negligible
d. None
Ans-c. Negligible
8. As the resistance of a coil increases the Q factor:-
a. Increases
b. Decreases
c. Remain same
d. None
Ans-b. Decreases
9. When a resistor connected parallel to a bulb gets in circuit:-
a. The bulb open circuited
b. bulb glows dimly
c. Brilliance remain same
d. None
Ans-c. Brilliance remain same
10. The state of charge of Ni-Cd battery can be found out by:-
a.Open circuit voltage
b. Amount of gassing
c.Measured discharge test
d. Specific gravity
Ans- c.Measured discharge test