Deck 1: Electrical Instrumentation

Question 1

Moving Iron instruments can be used on:

A)ac and dc both
B)ac only
C)dc only
D)none of the above

Answer 1

ac and dc both

Question 2

In spring control instruments, controlling torque:

A)can be adjusted easily
B)cannot be adjusted easily
C)remains the same
D)varies with the load

Answer 2

cannot be adjusted easily

Question 3

Chemical effect is used for the operation of:

A)voltmeter
B)ammeter
C)ampere hour meter
D)kwh meter

Answer 3

ampere hour meter

Question 4

The deflection torque can be produced by:

A)gravity control
B)spring control
C)air friction
D)magneitcally

Question 5

Moving coil instruments are:

A)permanent magnet type
B)dynamometer type
C)induction type
D)permanent magnet and dynamometer type

Question 6

For increasing the range of an ammeter, connect:

A)a high value resistance in series with the ammeter coil
B)a high value resistance in parallel with the ammeter coil
C)a low value resistance in parallel with the ammeter coil
D)a low value resistance in series with the ammeter coil

Question 7

A galvanometer can be used for measuring current and voltage of a circuit by:

A)shunt only
B)connecting high value of resistance in series only
C)shunt for measuring current and high resistance in series for voltage
D)without shunt and series resistance

Question 8

The energy consumption of MI instrument as compared to MC instrument is:

A)same
B)more
C)less
D)very small

Question 9

An ammeter requires a change of 4A in its coil to produce a pointer deflection of 8mm then its sensitivity is

A)2.5 mm/a
B)2.0 mm/a
C)0.5 mm/a
D)none of the above

Question 10

Electrostatic type instruments are mainly used for measurement of

A)heavy currents
B)low currents
C)low voltages
D)high voltages

Question 11

Measurement range of a voltmeter can be extended by using:

A)high current resistance
B)high series resistance
C)low shunt resistance
D)low series resistance

Question 12

Which of the following voltmeter have least power consumption:

A)moving iron
B)hot-wire
C)electrostatic
D)induction type

Question 13

Which of the following instruments have least torque/weight ratio:

A)dynamometer type
B)pmmc
C)attraction type moving iron
D)repulsion type moving iron

Question 14

Fluid friction damping can be used in

A)horizontally mounted instruments
B)vertically mounted instruments
C)both horizontally mounted instruments and vertically mounted instruments
D)none of the above

Question 15

The ratio and phase angle errors in potential transformer may be reduced by

A)increasing the exciting current
B)increasing the resistance and leakage reactance in the transformer
C)by not employing turns compensation
D)none of the above

Question 16

A voltmeter should have

A) low internal resistance
B) high internal resistance
C) electrostatic plates
D) a sensitive amplifier

Question 17

The major advantage of electromagnet type meter over a permanent magnet meter is

A) the electromagnet meter costs much less
B)the permanent magnet meter has a more sluggish coil
C) the electromagnet meter need not be aligned with the earth's magnetic field
D) the electromagnet meter is more rugged

Question 18

The change in the direction of a compass needle, when a current carrying wire is brought near, is called

A) electromagnetic deflection
B) electroscopic force
C)magnetic force
D) electrostatic force

Question 19

The use of _____ instruments is merely confined within laboratories as standardizing instruments.

A)absolute
B)indicating
C)recording
D)integrating

Question 20

Which of the following instruments indicate the instantaneous value of the electrical quantity being measured at the time at which it is being measured ?

A)absolute instruments
B)indicating instruments
C)recording instruments
D)integrating instruments

Question 21

_____ instruments are those which measure the total quantity of electricity delivered in a particular time.

A)absolute
B)indicating
C)recording
D)integrating

Question 22

Which of the following are integrating instruments ?

A)ammeters
B)voltmeters
C)wattmeters
D)ampere-hour and watt-hour meters

Question 23

Which of the following essential features is possessed by an indicating instrument ?

A)deflecting device
B)controlling device
C)damping device
D)all of the above

Question 24

A _____ device prevents the oscillation of the moving system and enables the latter to reach its final position quickly

A)deflecting
B)controlling
C)damping
D)any of the above

Question 25

The spring material used in a spring control device should have the following property.

A)should be non-magnetic
B)most be of low temperature co-efficient
C)should have low specific resistance
D)all of the above