Test: Capacitors - JEE MCQ

Q = CV, where C is decided only by the geometrical factors

Alcohol and HCl are polar molecules since they have a net dipole moment towards a particular direction. Both water and benzene are non-polar molecules. But water is a conductor of electricity, whereas benzene is a dielectric (insulator).

Definition based

C=(Kε0A/d)∝K/d
Hence,C₁/C₂=d2/d1=(d/3)d=3
C₂=3C₁

Capacitance of an isolated spherical conductor =4π€R , where €=permittivity of vacuum
C=2×10^-6F
C=4π€R
4×3.14×8.85×10^-12×R=2×10^-6
R=2×10^-6/4×3.14×8.85×10^-12
=1.8×10⁴ m

Given, charge =q=8×10−18C and Capacitance =C=100μF
Here the work done is the energy stored in the capacitor. i.e,
W=q^2​/C= (8×10−18)²/100×10⁻⁶​=32×10⁻³²J

Mica capacitors are preferred for high frequency circuits because they have low ohmic losses and less reactance.

Q = CV

W = Energy stored in the capacitor