A student connects a long air cored - coil of mangan in wire to a 100 V D.C. supply and records a current of 25 amp. When the same coil is connected across 100 V. 50 Hz a.c. the current reduces to 20 A , the reactance of the coil is____________
A. 4 W
B. 3 W
C. 5 W
D. None of the above
Answer:B
A student connects a long air cored - coil of mangan in wire to a 100 V D.C. supply and records a current of 25 amp. When the same coil is connected across 100 V. 50 Hz a.c. the current reduces to 20 A , the reactance of the coil is____________
A. 4 W B. 3 W C. 5 W D. None of the above