1. Consider an electromagnet capable of producing a maximum magnetic field of 2.
ID: 1590967 • Letter: 1
Question
1. Consider an electromagnet capable of producing a maximum magnetic field of 2.50 T. A circular loop of wire with a diameter of 9.50 cm is placed between the poles of the electromagnet. What is the induced EMF in the loop, if the electromagnet is turned on to full strength in 13.20 milli-seconds? Assume the loop is perpendicular to the magnetic field. Calculate the answer in volts (V) and rounded to three significant figures.
2. Consider a 12.5 cm long metal bar moving horizontally across a vertical magnetic field at a speed of 7.40 m/s. The magnetic field strength is 2.45 T. If the ends of the bar are connected to a 13.20 ohm resistor, find the power dissipated in the resistor while the bar is moving. Calculate the answer in watts (W) and rounded to three significant figures.
Explanation / Answer
1) Induced EMF in loop = Rate of change of flux
= d(NBA) / dt
= NA dB / dt
= 1 * (pi * (0.095/2)^2 ) (2.50) / (0.0132)
= 1.34 volt
2) Indduced emf in bar = B L v
e = 2.45 x 0.125 x 7.40
= 2.27 volt
I = e/ R = 2.27/13.2 = 0.172 A
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.