PHEP 25B

Question 1

Meter errors of the same magnitude may be caused by: a) excessive friction b) parallax c) a failure to zero the instrument d) all of the above

Answer 1

d) all of the above ref: p. 23

Question 2

Most AC ammeters generally have a sensitivity range of:

a) 5 amps
b) 10 amps
c) zero amps
d) varies

Answer 2

a) 5 amps ref: p. 8

Question 3

The resistance of an ammeter must be:

a) very low
b) very high
c) middle range
d) none of the above

Answer 3

a) very low ref: p.13

Question 4

The resistance of a voltmeter must be:

a) low
b) medium

d) none of the above

Answer 4

c) great ref: p. 13

Question 5

The DC wattmeter readings is equal to:

a) P = E x I
b) P = E x I x Cos 0
c) P = E x I x Sin 0
d) P = E x I x Tan 0

Answer 5

a) P = E x I ref: p. 17

Question 6

The main parts of a simple D’Arsonal ammeter are the:

a) coil and permanent magnet
b) coil and flux lines
c) flux lines and permanent magnet
d) none of the above

Answer 6

a) coil and permanent magnet ref: p. 1

Question 7

Damping action is provided for magnetically in most:

a) D’Arsonval movements
b) time element meters
c) meter error measurement
d) Wheatstone Bridges

Answer 7

a) D’Arsonval movements ref: p. 6

Question 8

A voltmeter indicates the amount of:

a) current
b) power
c) watts
d) voltage

Answer 8

d) voltage ref: p. 11

Question 9

A full scale on an ohmmeter is marked:

a) full scale
b) 100,000 ohms
c) zero ohms
d) 10 ohms

Answer 9

c) zero ohms ref: p. 13

Question 10

A wattmeter indicates the amount of:

a) meter error
b) voltage
c) amperes
d) power

Answer 10

d) power ref: p. 17

Question 11

A current limiting resistor connected in series with a voltmeter is called a:

a) resistor
b) multiplier
c) ohmmeter
d) opposition resistor

Answer 11

b) multiplier ref: p. 11

Question 12

Precision measurements of resistance my be obtained by using a:

a) resistor
b) multiplier
c) ohmmeter
d) Wheatstone Bridge circuit

Answer 12

d) Wheatstone Bridge circuit ref: p. 18

Question 13

Ammeters are always connected in:

a) series
b) parallel
c) series parallel
d) compound

Answer 13

a) series ref: p. 1

Question 14

Voltmeters are always connected in:

a) series-compound
b) compound
c) series
d) parallel

Answer 14

d) parallel ref: pg. 1

Question 15

The resistor connected in parallel with an ammeter in order to extend its range is called a/an:

a) detector
b) parallel shunt
c) ammeter shunt
d) ammeter multiplier

Answer 15

c) ammeter shunt ref: p. 8

Question 16

One of the common problems in reading a meter is:

a) parallax
b) coil deflection
c) meter tension
d) spring tension

Answer 16

a) parallax ref: p. 23

Question 17

Why do you short the leads of an ohmmeter?

a) to set the meter to read zero ohms by adjusting the zero adjustment
b) to test the multiplier
c) to test the shunt
d) to test the deflection

Answer 17

a) to set the meter to read zero ohms by adjusting the zero adjustment ref: p. 13

Question 18

What is a meter?

a) it is used to measure DC only
b) it is mainly just a transformer
c) it is mainly just a coil
d) it is an integrating device to measure electrical energy

Answer 18

d) it is an integrating device to measure electrical energy ref: p. 1

Question 19

An ohmmeter differs from an ammeter and voltmeter in that::

a) it has no transformer
b) it provides its own source of power and it contains other auxiliary circuits
c) it measures compound circuits only
d) sets up a strong magnetic field

Answer 19

b) it provides its own source of power and it contains other auxiliary circuits ref: p. 1

Question 20

Damping torque is the torque necessary to prevent:

a) overshooting the vane meters
b) a meter pointer from excessive oscillation and instability
c) control torque
d) hairspring burn-out

Answer 20

b) a meter pointer from excessive oscillation and instability Ref: p. 6