1. Which of the following is a scalar quantity?
Answer:
Explanation:
Electrostatic potential, unlike electric field or force, is a scalar quantity. It has magnitude but no direction.
2. The work done in moving a charge against the electric field is stored as:
Answer:
Explanation:
The work done against an electric field gets stored as electric potential energy of the charge.
3. A capacitor stores energy in the form of:
Answer:
Explanation:
A capacitor stores energy in the electrostatic field between its plates.
4. The SI unit of capacitance is:
Answer:
Explanation:
The SI unit of capacitance is Farad, represented as F.
5. If the separation between the plates of a capacitor is halved, its capacitance:
Answer:
Explanation:
The capacitance of a parallel plate capacitor is inversely proportional to the distance between its plates. So, halving the distance doubles the capacitance.
6. A dielectric material is introduced between the plates of a capacitor. What happens to its capacitance?
Answer:
Explanation:
Introducing a dielectric material increases the capacitance as it reduces the effective electric field between the plates.
7. Which of the following materials will be the best choice for a dielectric material in a capacitor?
Answer:
Explanation:
Mica is a good dielectric material due to its high dielectric constant and insulating properties.
8. The ability of a body to store an electrical charge is called:
Answer:
Explanation:
Capacitance is the measure of a body's ability to store an electric charge.
9. In a charged capacitor, if the voltage across its plates is doubled, the stored energy will:
Answer:
Explanation:
The energy stored in a capacitor is directly proportional to the square of the voltage. Hence, doubling the voltage will quadruple the energy.
10. Equipotential surfaces are:
Answer:
Explanation:
Equipotential surfaces are always perpendicular to the electric field lines at every point.
11. The work done in moving a charge between two points on an equipotential surface is:
Answer:
Explanation:
Since the potential difference between any two points on an equipotential surface is zero, the work done is also zero.
12. If three capacitors are connected in series, the overall capacitance will be:
Answer:
Explanation:
For capacitors in series, the reciprocal of the total capacitance is the sum of the reciprocals of individual capacitances.
13. What is the potential difference across a conductor in electrostatic equilibrium?
Answer:
Explanation:
In electrostatic equilibrium, there is no net motion of charges, and hence the potential difference across a conductor is zero.
14. The electric potential due to a point charge is V. If the distance from the charge is doubled, the electric potential becomes:
Answer:
Explanation:
The electric potential due to a point charge is inversely proportional to the distance. Thus, doubling the distance reduces the potential to half.
15. When a dielectric is inserted in a capacitor, the electric field between the plates:
Answer:
Explanation:
The introduction of a dielectric reduces the effective electric field due to its polarization.
16. The voltage across a capacitor's plates is V and its capacitance is C. The energy stored in the capacitor is given by:
Answer:
Explanation:
The energy (U) stored in a capacitor is given by U = 0.5*C*V^2.
17. If the distance between the plates of a capacitor is increased, the voltage between the plates:
Answer:
Explanation:
For a charged capacitor, if the distance is increased, the electric field between the plates and hence the voltage will increase.
18. A capacitor is said to be charged when:
Answer:
Explanation:
Charging a capacitor means giving equal and opposite charges to its plates.
19. Capacitance of a parallel plate capacitor depends on:
Answer:
Explanation:
Capacitance is directly proportional to the area of the plates and inversely proportional to the distance between them.
20. Electrostatic potential is a measure of:
Answer:
Explanation:
Electrostatic potential at a point is defined as the work done in bringing a unit positive charge from infinity to that point without acceleration.