Ohm’s Law MCQs

1. The formula to find current (I) when the values of voltage (V) and Resistance (R) are known is

1. I = VR
2. I = V/R
3. I = R/V
4. V = IR

2. An electric heater draws 3.6 A from a 110 V source. The resistance of the heating element is approximately

1. 30.5 Ω
2. 385 Ω
3. 31 Ω
4. 3.1 Ω

3. When there is 12 mA of current through a 1.2 kΩ resistor, the voltage across the resistor is

1. 100 V
2. 10 V
3. 14.4 V
4. 1.4 V

4. Approximately how many milliamperes of current flow through a circuit with a 40 V source and 6.8 kΩ of resistance?

1. 5.9 mA
2. 590 mA
3. 27.2 mA
4. 59 mA

5. A resistor is connected across a 50 V source. What is the current in the resistor if the colour code is red, orange, orange, silver?

1. 214 mA
2. 21.4 mA
3. 2 mA
4. 2.2 mA

6. How much resistance is required to limit the current from a 12 V battery to 3.6 mA?

1. 2.2 kΩ
2. 22 kΩ
3. 3.3 kΩ
4. 33 kΩ

7. What is the approximate resistance setting of a rheostat in which 650 mA of current flows through a 150 V source?

1. 23
2. 230
3. 9.7
4. 97

8. What is the voltage source for a circuit carrying 2 A of current through a 36 ohm resistor?

1. 7.2 V
2. 72 V
3. 1.8 V
4. 18 V

9. How much voltage is needed to produce 2.5 A of current through a 200 Ω resistor?

1. 80 V
2. 8 V
3. 50 V
4. 500 V

10. If 750 µA is flowing through 11 kΩ of resistance, what is the voltage drop across the resistor?

1. 82.5 V
2. 8.25 V
3. 14.6 V
4. 146 V

11. Ohm’s law is followed by

1. Metal rectifier
2. Copper electrode
3. Crystal detector
4. Arc lamp

12. The condition in ohm’s law is that

1. The temperature should remain constant
2. Ratio of V/I should be constant
3. The temperature should vary
4. Current should be proportional to voltage

13. Correct form of ohm’s law is

1. I = VR
2. V ∝ I
3. V = IR
4. Both (b) and (c)

14. Ohm’s law is applicable to

1. Semiconductors
2. Vacuum tube
3. Electrolytes
4. None of these

15. A current source and a resistor are connected in series. Suppose that is I_s = 3A and R=7 ohm. What is the voltage V across the resistor?

1. 3 V
2. 21 V
3. 7 V
4. 7.3 V

16. 1 Volt equals

1. 1 joule/1 coulomb
2. 1 watt/1 ohm
3. 1joule/1watt
4. 1watt/1coulomb

17. ohm’s law is applicable to

1. Resistive circuits
2. Reactive circuits
3. Both resistive circuits & reactive circuits 
4. None of these

18. According to ohm’s law

1. The voltage is constant to current
2. The voltage is proportional to current
3. Voltage is inversely proportional to current
4. The voltage is proportional to resistance

19. In a circuit a 33 Ω resistor carries a current of 2A. The voltage across the resistor is

1. 33 V
2. 66 V
3. 80 V
4. 132 V

20. If the energy is supplied from a source, whose resistance is 1 ohm, to a load of 100 ohms the source will be

1. A voltage source
2. A current source
3. Both of above
4. None of the above