Capacitor | MCQs

Explanation

- Capacitance with dielectric: C = εr · C₀, where C₀ is the capacitance without dielectric.

- If the dielectric is removed, capacitance becomes C₀ = C / εr. 

So, the new capacitance is C divided by εr.

Explanation

If the RC value is small in a circuit, the capacitor charges fastly. 

RC time constant: The time constant in an RC circuit is represented by the product of resistance (R) and capacitance (C). 

Charging speed: A smaller RC value means the capacitor charges faster. 

Large RC value: Conversely, a large RC value indicates a slower charging process for the capacitor. 

Explanation

To find the energy stored in a capacitor, we use the formula:

E=1/2​CV^2

Where:

• $\mathrm{<br>}$

• $V=100\text{V}$

Calculation:

$$E = frac{1}{2} times 4 times 10^{-6} times (100)^2$$E=1/2​×4×10^−6×10000
E=2×10^−6×10000

$$=0.02\text{J}$$

Explanation

 When capacitors are connected in parallel, their capacitances add up directly:

C_eq = C₁ + C₂ + C₃ = 2 + 2 + 2 = 6 µF

Explanation

Capacitance depends on area of plates, distance between them, and the dielectric (medium) used.

It does not directly depend on the electric field, which is a result of the charge and voltage, not a factor in determining capacitance.

Explanation

Mica is a dielectric material that increases the capacitance when placed between capacitor plates.

It does so by reducing the electric field and allowing the capacitor to store more charge for a given voltage.

Explanation

Explanation

A capacitor consists of two conductors separated by a non-conductive region.

It stores electrical energy in an electric field between the conductors.

Explanation

Explanation

In an oscillating LC circuit, the maximum energy stored in the capacitor during one cycle is equal to the total stored energy (U) in the circuit.

This is because the total energy oscillates between the capacitor and the inductor, with the total energy remaining constant in an ideal, lossless LC circuit.