2
1-8. Current through a meter results in the
pointer. In d'Arsonval meter movement,
what force produces this deflection?
1. Thermocouple action
2. Electrostatic repulsion
3. Mechanical spring tension
4. The interaction of magnetic fields
1-9. The hairsprings in a d'Arsonval meter
movement perform which of the following
functions?
1. They keep the pointer in the position
of the last indication when current is
removed
2. They aid the movement of the pointer
when there is current through the
meter
3. They make electrical connections to
the meter movement
4. All of the above
Figure 1-B.Compass and wire (ac).
IN ANSWERING QUESTIONS 1-10 AND 1-11,
REFER TO FIGURE 1-B.
1-10. If the frequency of the ac source is 5 Hz,
how will the compass needle react when
S1 is closed?
1. It will swing back and forth
2. It will point directly at the wire
3. It will point directly away from the
wire
4. It will vibrate rapidly around magnetic
north
1-11. If the frequency of the ac source is 200
Hz, how will the compass needle react
when S1 is closed?
1. It will swing back and forth
2. It will point directly at the wire
3. It will point directly away from the
wire
4. It will vibrate rapidly around magnetic
north
1-12. What device allows a d'Arsonval meter
movement to measure ac by converting ac
to pulsating dc?
1. A pulsator
2. A modulator
3. A rectifier
4. A converter
1-13. What is meant by the term "meter
damping"?
1. Moistening the felt pads
2. Smoothing the oscillations of the
pointer
3. Preventing excessive current through
the coil
4. Compensating for electromagnetic
induced interference
1-14. Which of the following methods is used to
dampen a meter?
1. Mount the meter in a mu-metal case
2. Install a fuse in one of the input leads
3. Incorporate an airtight chamber
containing a van
4. Provide a fluid reservoir and sponge
arrangement next to the pads
