Week 6 Homework Assignment
- What is the direction of the induced current in the circular loop due to
the current shown in each part of Fig. 1?
Fig.1
- The moving rod in Fig.2 is 12.0cm long and moves with a speed of 15.0cm/s.
If the magnetic field is 0.800T, calculate (a) the emf developed, and
(b) the electric field in the rod.
Fig.2
- A 31.0-cm diameter coil consists of 20 turns of circular copper wire 2.6mm
in diameter. A uniform magnetic field, perpendicular tot he plane of the
coil, changes at a rate of 8.65 x 10-3T/s. Determine (a)
the current in the loop, and (b) the rate at which thermal energy is
produced.
- High-intensity desk lamps are rated at 40W but required only 12V. They
contain a transformer that convert 120V household voltage. (a) Is the
transformer step-up or step-down? (b) What is the current in the
secondary when the lamp is on? (c) What is the current in the
primary? (d) What is the resistance of the bulb when on?
- How long would it take a message sent as radio waves from Earth to reach (a)
Mars, (b) a spacecraft near Saturn?