Capacitor - Electromagnetism PYQ | Physics Exams

Four capacitors with capacitances \(C_1=l \propto \mathrm{F}, C_2=1.5 \propto \mathrm{F}, C_3=2.5 \propto \mathrm{F}\) and \(C_4=0.5 \propto \mathrm{F}\) are connected as shown and are connected to a \(30 \mathrm{~V}\) source. The potential difference between points \(a\) and \(b\) is

In the given circuit, if the potential difference between A and B is 80 V, then the equivalent capacitance between A and B and the charge on 10 \(\propto\) F capacitor respectively, are

A 60 \(\mu\)F parallel plate capacitor whose plates are separated by 6 mm is charged to 250 V, and then the charging source is removed. When a slab of dielectric constant 5 and thickness 3 mm is placed between the plates, find the change in the potential difference across the capacitor.

A capacitor of capacitance \(C_1=1 \mu \mathrm{F}\) is charged using a 9 V battery. \(C_1\) is, then removed from the battery and connected to capacitors \(C_2\) and \(C_3\) of \(2 \mu \mathrm{F}\) and \(3 \mu \mathrm{F}\), respectively as shown in the figure. Find the charge on \(C_3\) after equilibrium has reached is

The capacitance between the points A and B in the following figure.

Eight capacitors each of capacity $2 \mu \mathrm{~F}$ are arranged as shown in figure. The effective capacitance between $A$ and $B$ is

A capacitor of capacitance $2 \mu \mathrm{~F}$ is charged to 50 V and then disconected from the source. Later the gap between the plates of the capacitor is filled with a dielectric material. If the energy stored in the capacitor is decreased by $25 \%$ of its initial value, then the dielectric constant of the dielectric material is

The radii of the inner and outer spheres of a spherical capacitor are 8 cm and 9 cm respectively. The outer sphere is earthed and the inner sphere is charged. If the space between the concentric spheres is filled with a liquid of dielectric constant 5 , the capacitance of the capacitor is

The energy stored in a capacitor is $W$. To double the charge on the plates of the capacitor, the additional work to be done is

A wire of length 10 m carrying current of 1 A is bent in to a circular loop. If a magnetic field of $2 \pi \times 10^{-4} \mathrm{~T}$ is applied on the loop, then the maximum torque acting on it is

One of the two identical capacitors having the same capacitance $C$, is charged to a potential $V_1$ and the other is charged to a potential $V_2$. If they are connected with their like plates together, then the decrease in the electrostatic potential energy of the combined system is

The capacitance of a spherical capacitor is 100 pF . If the spacing between the two spheres is 1 cm , then the radius of the inner sphere of the capacitor is