PYQ NEET- Problem Solving Modern Physics

1. A parallel plate capacitor is filled with two dielectrics as shown in the figure. The dielectric constants of the dielectrics are $K_1$ and $K_2$ respectively. Find the capacitance of the capacitor.

The capacitance of a parallel plate capacitor is given by

$$C = \frac{\varepsilon_0 A}{d}$$

where $\varepsilon_0$ is the permittivity of free space, $A$ is the area of the plates, and $d$ is the distance between the plates.

In this case, the capacitor is filled with two dielectrics, so the capacitance is given by $ C = \frac{\epsilon_0 A}{d} \left( \frac{1}{k_1} + \frac{1}{k_2} \right)^{-1} $

$$C = \frac{\varepsilon_0 A}{d(1 - \frac{K_1}{K_2})}$$

2. A proton and an electron are released from rest in a uniform electric field. The ratio of their acceleration is

The acceleration of a charged particle in an electric field is given by

$$a = \frac{F}{m}$$

where $F$ is the force on the particle and $m$ is the mass of the particle.

The force on a charged particle in an electric field