Electricity and Magnetism - SS2 Physics Past Questions and Answers - page 1

To calculate the electric field, we can use Coulomb's law:

Electric field (E) = (k x |q|) / r2, where k is the electrostatic constant, q is the charge, and r is the distance.

   Substituting the values, we have:

   E = (9 x 109 Nm2/C2 x 3 x 10-6 C) / (0.05 m).

   E ≈ 1.08 x 105 N/C

The charge stored on a capacitor can be calculated using the formula:

   Q = C x V, where Q is the charge, C is the capacitance, and V is the potential difference.

   Plugging in the values, we have:

   Q = 12 x 10-6 F x 24 V

   Q = 2.88 x 10-4 C

The change in electric potential energy can be calculated using the formula:

   ΔPE = q x ΔV, where ΔPE is the change in potential energy, q is the charge, and ΔV is the change in potential.

   Plugging in the values, we have:

   ΔPE = 6 x 10-6 C x (-120 V)

   ΔPE = -7.2 x 10-4 J

The electric potential can be calculated using the formula:

   V = (k x q) / r, where V is the potential, k is the electrostatic constant, q is the charge, and r is the distance.

   Plugging in the values, we have:

   V = (9 x 109 Nm2/C2 x 2 x 10-9 C) / 4 m

   V = 4.5 x 103 V