Weizi abcd line

(1) direction adcba (2) e = 2π nbsncos2π nt (3) nbs/(r+r) (4) 2π 2n2b2s2n/(r+r)

(1) According to the right-hand rule, the direction can be judged as adcba；;

(2) The maximum value is E=NBS, the starting time is at the maximum position, and E = 2πnbsncos 2πnt；;

(3) the amount of charge flowing through the resistor r;

(4) The work done by external force is equal to the work done by current when the coil rotates once. If yes, W=2π 2 N 2 B 2 S 2 n 2 /(R+r).