# Physics GK 20 - Electricity

1. Which of the following is the commercial unit of electric power?
[A] Joule
[B] KWh
[C] Watt
[D] Ampere

2. What is the work done to move a unit charge from point to another called as?
[A] Current
[B] Resistance
[C] Conductance
[D] Potential Difference

3. As per Ohm’s law, if the resistance of a conductor is doubled, what will be the effect on the current flowing through it?
[A] it gets doubled
[B] it gets halved
[C] it increases 4 times
[D] No change

4. Which of the following metals is mostly used for filaments of electric bulbs?
[A] Copper
[B] Silver
[C] Nickel
[D] Tungsten

5. What is the property of a conductor to resist the flow of charges known as?
[A] Conductance
[B] Conductivity
[C] Resistance
[D] Electric Potential

6. What of the following represents Ohm’s law (V= potential difference and I=current)?
[A] V = I 2
[B] V = 1/I
[C] V/I = constant
[D] None of the above

7. Which of the following is true about metals?
[A] They are good conductors of electricity
[B] They have low resistivity
[C] Both a and b
[D] None of the above

8. Which of the following is an example of insulator?
[A] Diamond
[B] Mercury
[C] Iron
[D] Chromium

9. Which of the following is true about the force between two point charges as per the Coulomb’s law?
[A] inversely as the square of the distance between the charges
[B] directly proportional to the product of the magnitude of the two charges
[C] Both a and b
[D] None of the above

10. What is the value of permittivity of free space?
[A] 8.854 × 10–10 C2 N–1 m–2
[B] 8.854 × 10–11 C2 N–1 m–2
[C] 8.854 × 10–12 C2 N–1 m–2
[D] 8.854 × 10–13 C2 N–1 m–2