1. The kWh meter can be classified as a/aninstrument
(a) deflecting (b) digital
(c) recording (d) indicating
2. The moving system of an indicating type of
electrical instrument is subjected to :
(a) a deflecting torque
(b) a controlling torque
(c) a damping torque
(d) all of the above
3. The damping force acts on the moving
system of an indicating instrument only when
it is :
(a) moving (b) stationary
(c) near its full deflection
(d) just starting to move.
4. The most efficient form of damping
employed in electrical instruments is :
(a) air friction
(b) fluid friction
(c) eddy currents
(d) none of the above.
5. Moving iron instruments can be used for
measuring :
(a) direct currents and voltages
(b) alternating current and voltages
(c) radio frequency currents
(d) both (a) and (b).
6. Permanent-magnet moving-coil ammetere
have uniform scales because :
(a) of eddy current damping
(b) they are spring-controlled
(c) their deflecting torque varies directly
as current
(d) both (b) and (c).
7. The meter that is suitable for only direct
current measurements is :
(a) moving-iron type
(b) permanent-magnet type
(c) electrodynamic type
(d) hot-wire type.
8. A moving coil voltmeters measures—
(a) only a.c. voltages
(b) only d.c. voltages
(c) both a.c. and d.c. voltages
10. The hot-wire ammeter :
(a) is used only for d.c. circuits
(b) is a high precision instrument
(c) is used only for a.c. circuits
(d) reads equally well on d.c. and/or a.c.
circuits.
ANSWERS1. c 2. d 3. a 4. c 5. d 6. d 7. b 8. b 9. c 10.