1.

An electric heater draws 3.5 A from a 110 V source. The resistance of the heating element is approximately
A. 385
B. 38.5
C. 3.1
D. 31

2.

If 750 µA is flowing through 11 k of resistance, what is the voltage drop across the resistor?
A. 8.25 V
B. 82.5 V
C. 14.6 V
D. 146 V

3.

The formula to find I when the values of V and R are known is
A. I = VR
B. I = R/V
C. V = IR
D. I = V/R

4.

A resistor is connected across a 50 V source. What is the current in the resistor if the color code is red, orange, orange, silver?
A. 2 mA
B. 2.2 mA
C. 214 mA
D. 21.4 mA

5.

Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 k of resistance?
A. 27.2 mA
B. 59 mA
C. 5.9 mA
D. 590 mA

6.

How much resistance is required to limit the current from a 12 V battery to 3.6 mA?
A. 3.3 k
B. 33 k
C. 2.2 k
D. 22 k

7.

What is the voltage source for a circuit carrying 2 A of current through a 36 resistor?
A. 1.8 V
B. 18 V
C. 7.2 V
D. 72 V

8.

What is the approximate resistance setting of a rheostat in which 650 mA of current flows with a 150 V source?
A. 9.7
B. 97
C. 23
D. 230

9.

How much voltage is needed to produce 2.5 A of current through a 200 resistor?
A. 50 V
B. 500 V
C. 80 V
D. 8 V

10.

When there is 12 mA of current through a 1.2 k resistor, the voltage across the resistor is
A. 14.4 V
B. 1.4 V
C. 100 V
D. 10 V
11.

A resistance of 3.3 M is connected across a 500 V source. The resulting current is approximately
A. 15.1 µA
B. 151 µA
C. 66 mA
D. 660 mA

12.

You are measuring the current in a circuit that is operated on an 18 V battery. The ammeter reads 40 mA. Later you notice the current has dropped to 20 mA. How much has the voltage changed?
A. 9 V
B. 900 mV
C. 0 V
D. 18 V

13.

The current through a flashlight bulb is 40 mA and the total battery voltage is 4.5 V. The resistance of the bulb is approximately
A. 112
B. 11.2
C. 1.2
D. 18

14.

If you wish to increase the amount of current in a resistor from 120 mA to 160 mA by changing the 24 V source, what should the new voltage setting be?
A. 8 V
B. 320 V
C. 3.2 V
D. 32 V

15.

If 24 V are applied across a resistor and there are 10.9 mA of current, the resistance is
A. 220 k
B. 22 k
C. 2.2 k
D. 220


16.

How much resistance is needed to draw 17.6 mA from a 12 volt source?
A. 212
B. 6.8 k
C. 68
D. 680

17.

How much current is produced by a voltage of 18 kV across a 15 k resistance?
A. 1.2 A
B. 12 A
C. 120 mA
D. 12 mA

18.

A current of 200 µA through a 6.8 k resistor produces a voltage drop of
A. 34.4 V
B. 340 V
C. 13.6 V
D. 1.36 V

19.

Four amperes of current are measured through a 24 resistor connected across a voltage source. How much voltage does the source produce?
A. 960 V
B. 9.6 V
C. 96 V
D. 8 V
20.

Twelve volts are applied across a resistor. A current of 3 mA is measured. What is the value of the resistor?
A. 4
B. 400
C. 4 k
D. 4.4


21.

When 12 V are applied across a 68 resistor, the current is
A. 816 mA
B. 17.6 mA
C. 176 mA
D. 8.16 mA

22.

Approximately how much current flows through a 3.3 M resistor across a 30 V source?
A. 9 A
B. 90 A
C. 900 A
D. 9000 A

23.

A 120 V lamp-dimming circuit is controlled by a rheostat and protected from excessive current by a 3 A fuse. To what minimum resistance value can the rheostat be set without blowing the fuse? Assume a lamp resistance of 20 ohms.
A. 40
B. 4
C. 2
D. 20

24.

What is the approximate filament resistance of a light bulb if it operates from a 110 V source and 0.6 A of current is flowing?
A. 183
B. 18.3
C. 66
D. 6.6

25.

What is the approximate resistance of a rheostat if the voltage source is 18 V and the current is 220 mA?
A. 8.2 k
B. 820
C. 8.2
D. 82
Última modificación: martes, 19 de xullo de 2016, 3:17 PM