CK-12-Physics-Concepts - Intermediate

21.1. Electromotive Force http://www.ck12.org

1. Which of the following units are equivalent to those ofEMFproduced in a generator?
   (a)T·m/s
   (b)V·m^2 /s
   (c)J/s
   (d)A·Ω
   (e)T·m


2. A straight wire 0.500 m long is moved straight up through a 0.400 T magnetic field pointed in the horizontal
   direction. The speed of the wire is 20.0 m/s.
   (a) WhatEMFis induced in the wire?
   (b) If the wire is part of a circuit with a total resistance of 6. 00 Ω, what is the current in the circuit?


3. A straight wire, 25.0 m long, is mounted on an airplane flying at 125 m/s. The wire moves perpendicularly
   through earth’s magnetic field(B= 5. 00 × 10 −^5 T). What is theEMFinduced in the wire?


4. A straight wire, 30.0 m long, moves at 2.00 m/s perpendicularly through a 1.00 T magnetic field.
   (a) What is the inducedEMF?
   (b) If the total resistance of the circuit is 15. 0 Ω, what is the current in the circuit?

• electromotive force: The potential energy per unit charge that produces a flow of electricity in a circuit,
  expressed in volts.


• induced current:The electric current generated in a loop of conducting material by movement of the loop
  across a magnetic field.