Electromagnetic Induction

Problem 173: An airplane travels at a speed of 1000 kph in a region where the earth's magnetic field is \(5.0\times10^{-5}\,T\) and is nearly vertical. What is the potential difference induced between the wing tips of the airplane, which is 20 m apart?

Problem 176: A metal disk of 30 cm radius rotates at an angular velocity of 1200 rpm across a uniform vertical magnetic field of flux density \(0.5\,Wb/m^2\). Calculate the voltage induced between the rim and the center of the disk.

Problem 179: The field winding of a DC generator is wound with 900 turns and has a resistance of 50 ohms. If the winding is excited from a 240 V dc source, the magnetic flux linking the coil is 4 mWb. Determine the self-inductance of the coil.

Problem 180: A coil of 1000 turns is uniformly wound on a ring of non-magnetic material, the mean diameter being 20 cm. The cross sectional area of the coil is 4 square cm. Determine the self-inductance of the coil.

Problem 183: A coil of inductance 8 mH, produces \(80\,\mu Wb\) of magnetic flux. Of this total flux, \(60\,\mu Wb\) are linked to a second coil of inductance 2 mH, how much is the mutual inductance between coils?

Problem 185: Two identical coils with self-inductance of \(250\,\mu H\) each are connected in series. When connected series aiding, the equivalent inductance is \(550\,\mu H\) and \(450\,\mu H\) when connected series opposing. How much is the coupling coefficient of two coils?

Problem 186: A cylinder whose radius is 2 cm and altitude of 100 cm. is uniformly wound with 2500 turns of wires in a single layer. A second layer of 100 turns and of much finer wires is wound over the first near its center. Calculate the mutual inductance of the two coils.

Problem 193: A solenoid 500 cm long and 10 cm in diameter is wound with 1500 turns. Find the energy stored in the magnetic field when a current of 5 A flows.

Problem 194: A coil of 250 turns is wound on a closed iron ring whose cross sectional area is \(20\,cm^2\) and mean length of 100 cm. Determine the energy stored in the magnetic field if a current of 2 A is passed through it. Assume the permeability of iron is 900.

Two coils of inductance 8 H and 10 H are connected in parallel. If their mutual inductance is 4H, determine the equivalent inductance of the combination if mutual inductance assists the self- inductance.

A solenoid 500 cm long and 10 cm in diameter is wound with 1,500 turn. Find the energy stored in the magnetic field when a current of a 5 A flows.

A coil of 50 turns having a mean diameter of 3 cm is placed coaxially at the center of a solenoid 60 cm long wound with 2,500 turns and carrying a current of 2 A. What is the mutual inductance of the arrangement?

A 20 mH inductor draws a current of \(i(t) = 100\sin 100t\). Find the voltage equation.

Two identical coupled coils have an equivalent inductance of 80mH when connected in series aiding and 35mH in series opposing. What is the value of the coefficient of coupling K.

Two coupled coils have self-inductances \(L_1 = 50\) mH and \(L_2 = 200\) mH, and a coefficient of coupling k = 0.50. If \(i_1 = 5\sin 400t\) A, find the voltage at coil 2.