Question

QUESTION 3 Our big lecture-table solenoid has 560 tums, each with 60 mm diameter, spaced tightly to only be 160 mm Long (left-to-right) The standard power supply needs 10.2 Volt to push 6.0 A current thru the solenoid wire, clockwise as seen from the night [a) show that the magnetic field in the solenoid space used to be 0.02639 T leftward (-x)] [b) what direction is the induced electric field, inside the solenoid cylinder : 1) before turnoff: 2) during turnoff 3) after turnoff complete (c) what voltage magnitude was induced in the solenoid's wire coil? [d) show that the solenoid's self-inductance is 0.006 9540 ) e) What is the relaxation time for that solenoid, by itself (if we switched it off, rather than adjusting it off)? O 02833 0 244 s 0.004 096 s

Answer 1

3 Giren - N= 560 8=20mm 230x10 L= 160mm = 160x10 3 m :: n(no of tums per unit length) - N 560 160x103 3500 a) B = MonI 2 47X107 x 35000 6 B = 0.02639 T], (-) b) induced Emf: B = Mon I (mag. flux) Pm = BA = Mon I (182) $ E dla 2 O dom dt • Before tumff there will be no indemed E. f because mag. flux & not changing with time During tumoff there will be induced Ef. According to Leng's law, E. f will be in the disection cussent live clockwise) After tumoff again no enfor induced d) self induction inside the solenoid :- L = Mon²LA . = 42410-7x (3500)2 x 160x10 3 x 282 - 0.00 6964 2 m