18
2-37. When the leads of an ohmmeter are
placed across a resistor, that resistor adds
to the internal series coil resistance of the
meter. The pointer is deflected to the left
of its full-scale position, giving a reading
in ohms for the resistor being tested.
Which of the following reasons explains
why the pointer moves to less than full-
scale?
1. Because voltage in the meter circuit
is greater than full-scale voltage
2. Because current in the meter circuit
is greater than full-scale current
3. Because current in the meter circuit
is less than full-scale current
4. Because voltage in the meter circuit
is less than full-scale current
2-38. With the ohmmeter range switch set at R
X 100, the pointer of the meter indicates
850. What is the actual value of the
resistor?
1. 8.5 kilohms
2. 85
kilohms
3.
850
kilohms
4. 8.5 megohms
RANGE SCALE
RESISTOR VALUE
A.
R×1
50 kilohms
B.
R×10
500 kilohms
C.
R×100
5 megohms
Figure 2D.—Range scales and resistance values.
IN ANSWERING QUESTION 2-39, REFER
TO FIGURE 2D.
2-39. You are measuring resistors using range
settings as shown in the figure. What
condition listed in the figure, if any, will
cause the greatest amount of current to
move through the ohmmeter coil circuit?
1. A
2. B
3. C
4. None; they all allow the same
amount of current
2-40. Which of the following locations on the
meter scale provides the most accurate
reading for resistance?
1. To the far left side of the scale
2. To the far right side of the scale
3. Halfway between the left side and
center of the scale
4. Near the center of the scale
2-41. An ordinary ohmmeter is unsuitable for
measuring insulation resistance for which
of the following reasons?
1. Voltage is present in the conductors
attached to the insulating materials
being measured
2. Insulation resistance values are too
great for an ohmmeter to measure
3. Ohmmeter current will damage
insulation material
4. The accuracy of an ohmmeter is too
low to measure insulation resistance
