Q4. A cylindrical pot magnet is shown in Fig. b. The coil, which has 1000 turns and a resistance of 20 22, is connected
Posted: Sun Jul 03, 2022 12:08 pm
Q4. A cylindrical pot magnet is shown in Fig. b. The coil, which has 1000 turns and a resistance of 20 22, is connected to a constant-voltage source of 60 V DC. The plunger passes the point at which the airgap is 10 mm travelling upwards with a uniform velocity of 2.0 m/s. Make an estimate of the value of the current at this instant, assuming that the initial airgap length was 15 mm. Apportion the instantaneous input power into heat, magnetic-energy storage-rate and mechanical components. Hence estimate the magnetic force on the plunger. Ans: 80 W, -78.4 W, 118.4 W, 49.2 N [ Airgap 50 mm dia Fig. b Coil 59