Exam Primer

# 5.6 Power law, Resister Power Disipation

## Practice

B-005-06-01
Why would a large size resistor be used instead of a smaller one of the same resistance?
For better response time
For a higher current gain
For less impedance in the circuit
For greater power dissipation

B-005-06-02
How many watts of electrical power are used by a 12-VDC light bulb that draws 0.2 ampere?
2.4 watts
60 watts
24 watts
6 watts

B-005-06-03
The DC input power of a transmitter operating at 12 volts and drawing 500 milliamps would be:
20 watts
6 watts
500 watts
12 watts

B-005-06-04
When two 500 ohm 1 watt resistors are connected in series, the maximum total power that can be dissipated by the resistors is:
1 watt
2 watts
1/2 watt
4 watts

B-005-06-05
When two 500 ohm 1 watt resistors are connected in parallel, they can dissipate a maximum total power of:
1/2 watt
1 watt
2 watts
4 watts

B-005-06-06
If the voltage applied to two resistors in series is doubled, how much will the total power change?
increase four times
decrease to half
double
no change

B-005-06-07
If the power is 500 watts and the resistance is 20 ohms, the current is:
2.5 amps
10 amps
25 amps
5 amps

B-005-06-08
A 12 volt light bulb is rated at a power of 30 watts. The current drawn would be:
30/12 amps
18 amps
360 amps
12/30 amps

B-005-06-09
If two 10 ohm resistors are connected in series with a 10 volt battery, the power consumption would be:
5 watts
10 watts
20 watts
100 watts

B-005-06-10
One advantage of replacing a 50 ohm resistor with a parallel combination of two similarly rated 100 ohm resistors is that the parallel combination will have:
the same resistance but lesser power rating
greater resistance and similar power rating
the same resistance but greater power rating
lesser resistance and similar power rating

B-005-06-11
Resistor wattage ratings are:
calculated according to physical size
expressed in joules per second
determined by heat dissipation qualities
variable in steps of one hundred