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_____ 1. Suppose a magnetic field points from the left edge of this page to the

ID: 2121672 • Letter: #

Question



_____ 1. Suppose a magnetic field points from the left edge of this page to the right edge of this page. The force on a positive charge moving in a direction into the page would be:

Zero

Toward the top of the page

Toward the bottom of the page

Toward the left edge of the page

Out of the page.

_____ 2. Which of the following laws states that an induced electric current always opposes the change that caused the current?

Faraday's Law

Lenz's Law

Ampere's Law

Gauss's Law

The law of Transformers

_____ 3. A transformer has a primary (input) voltage of 110 VAC and a secondary voltage(output) of 6 VAC. If there are 440 turns on the primary, the number of turns on the secondary is:

a. 40

b. 2017

c. 110

d. 220

e. 24

_____ 4. Which of these types of electromagnetic radiation has the longest wavelength?

gamma rays

ultraviolet

radio waves

infrared

visible light

_____ 5. A wire loop rests on this page. An electromagnet is above the loop with the S pole facing downward. As viewed from above, which of these would create clockwise current in the loop?

Turn the electromagnet off

Increase the strength of the electromagnet

Move the electromagnet closer to the loop

A or C

B or C


______ 6. The outlet in your room provides 120 Volts RMS. RMS stands for:

Rolling mode sine

Regular mean standard

Really mean stuff

Root mean square

Right modulated sine


______ 7. In an RLC circuit, which of the following definitely decreases as frequency increases?

Resistance

Capacitive Reactance

Inductive Reactance

Impedance

Dissipated power

______8. One similarity between inductors and capacitors is that they both:

Have high reactance at high frequencies

Have high reactance at low frequencies

Store but do not use energy

Create energy in a circuit

Are measured in Henries

______ 9. An RC circuit consists of a 150 ohm resistor in parallel with an uncharged

22 %u03BCF capacitor connected through a switch to a 6 volt battery. When the switch is closed, the current in the circuit is:

a) high initially and falls to zero
b) low initially and rises to 6 Amperes
c) a constant 6 amperes
d) high initially and falls to 40 mA
e) low initially and rises to a number that can't be determined

______ 10. A 0.63 T magnetic field passes through a circular ring with radius 2.5 cm at an angle of 16 degrees with the normal to the ring. The magnitude of the magnetic flux through the ring is:

1.19 x 10-3 Wb

3.36 x 10-3 Wb

3.49 x 10-4 Wb

1.6 x 10-4 Wb

12.2 Wb


a) If point A is 5 cm from the wire, calculate the magnitude of the magnetic field at point A due to the wire.

b) In what direction is this field? Explain how you know

Explanation / Answer

1. Towards the top of the page

2. Lenz's Law

3. V1/V2=N1/N2; 110/6 = 440/N2 => N2= 24

4. Radio Waves

5. move the electromagnet closer to the loop

6.Root Mean Square

7. capacitive reactance

8. store but do not use energy

9. high initially and falls to zero

10. 0.63(Wb/m^2)*Area of loop(m^2)*cos(16deg) = 1.19x10^-3 Wb

11

a.for infinitely long wire

H=I/[2 *pi*r]=3.4/[2*pi*0.05]=10.8 A/m

b. out of the page (use right hand rule)