A capacitor consists of two circular metal disks, each of radius 15cm separated by 0.5mm (a) what is the capacitance of the device (b) what is the magnitude of the charge stored on each disk when the potential across the capacitor is 150V?

A Circular coil of wire consisting of 100 turns, each of radius 8.0cm carries a current of 0.40A. What is the magnitude of the magnetic field bar B at the centre of the coil?

A 100 turn closely wound circular cell of radius 10 cm carries a current of 3.2A (a) what is the field at the centre of the coil? (b) What is the magnetic moment of this coil? The coil is placed in a vertical plane and is free to rotate about a horizontal axis which coincides with its diameter. A uniform magnetic field 2 T in the horizontal direction exists such that initially the axis of the coil is in the direction of the field. The coil rotates through an angle of 90^(o) under the influence of the magnetic field (c) What are the magnitudes of the torques on the coil in the initial and final position? (d) What is the angular speed acquired by the coil when it has rotated by 90^(o) ? The moment of inertia of the coil is 0.1 kg m^(2) .

Three capacitors each of capacitance 9pF are connected in series a. What is the total capacitance of the combination? b. What is the potential difference across each capacitor, if the combination is connected to a 120V supply?

Three capacitors of capacitance 2pF, 3pF, and 4pF are in parallel a. What is the total capacitance of the combination? b. Determine the charge on each capacitor if the combination is connected to a 100V supply?