Question

QUESTION 5 A stack of neodymium button magnets (12 mm diameter, 75 mm tall) dropped from 0.200 m high, generates an average +2 375 Volt for 0.040 seconds, as it enters a lab coil that has 800 turns spread along 40 mm tall, each with 0.112 m circumference (28 mm long x 28 mm wide) [a) how much voltage aggregates along each loop?] b) Compute the magnetic field inside the magnet stack [c) if the stack's magnetic North pole was down, what direction of Electric field was induced as the stack entered (as seen from above)?) [d) if the stack takes 0.0375 s to exit the coil (downward), what average voltage would be generated?1 01.050 T O 96.94 KT O 0.151 T O 672 KT O 0.042 T O 840 T O 121 T O 0.0265 T

Answer 1

A) Assuming the coil is made of a uniform kind of material, the voltage across each loop will be the same.

Here, we have 800 turns.

Total voltage = 2.375 V

So,

Voltage across a single loop = 2.375/800 = 0.00297 V

B) The emf generated in a loop is given by

e = B*A/t

Here

e = 0.00297 V

A = 0.028*0.028 = 0.000784 m^2

t = 0.04 s

So,

B = et/A = 0.15153 T

Option C is correct.

C) since the north pole is falling down, according to the Lenz' law, the current generated will be in the counter clockwise direction as viewed from above.

D)

If t = 0.0375 s,

E = N*BA/t = 800*0.15153*(0.028*0.028)/0.0375 = 2.534 V