Short notes
Objective questions (Answers are given below)
- The kWh meter can be classified as a/aninstrument
:
(a) deflecting (b) digital
(c) recording (d) indicating - 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 - 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.The most efficient form of dampingThe most efficient form of damping
- 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. - 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). - 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). - 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. - A moving coil voltmeters measures—
(a) only a.c. voltages
(b) only d.c. voltages
(c) both a.c. and d.c. voltages
(Principles of Elect. Engg. Delhi Univ.)
1.c 2. d 3. a 4. c 5. d 6. d 7. b 8. b