Electromagnetic Theory

Use this for “A disk of radius 10 cm carries 2 μC/m². Find the field on its axis 5 cm from its center, and compare it with a wide sheet’s field.”

Use this for “A 4 nC charge is held 2 cm above a large grounded metal plate. Find the force pulling it toward the plate, the induced charge per area just below it, and the total induced charge.”

Use this for “Charges of +3 nC and −3 nC sit 2 mm apart. Find the potential 5 cm from their center, 45° from the axis on the + side.”

Use this for “A wire of radius 3 mm carries 30 A spread evenly over its cross-section. Find B 2 mm and 6 mm from its axis.”

Use this for “A toroid of 800 turns carries 1.5 A. Find the field 12 cm from its center, inside the windings.”

Use this for “A 120-turn coil of area 25 cm² carries 0.4 A in a 0.3 T field, its moment at 60° to the field. Find the torque and the energy.”

Use this for “Round capacitor plates of radius 4 cm charge with a current of 1.5 A. Find the displacement current and B 2.5 cm from the axis, between the plates.”

Use this for “A 5 W radio transmitter sends its power evenly in all directions. Find the intensity and the electric field amplitude 300 m away.”

Use this for “Light passes straight from water (n = 1.33) into diamond (n = 2.42). What fraction of its intensity is reflected, and what fraction goes through?”