margin-top: 12pt;" CLASS="Normal-0020Text">Exam

Name___________________________________

MULTIPLE CHOICE.  Choose the one alternative that best completes
the statement or answers the question.

Figure 29.1

1)  

 
In Fig. 29.1, a wire and a 10- resistor are used to form a circuit in the shape of
a square, 20 cm by 20 cm. A uniform but nonsteady magnetic field is
directed into the plane of the circuit. The magnitude of the magnetic
field is decreased from  1.50 T to  0.50 T in a time interval
of  32 ms. The average induced current and its direction through
the resistor, in this time interval, are closest to:  

 
1)  _______

A)  

 

190 mA, from a to b

B)  

 

75 mA, from b to a

C)  

 

130 mA, from a to b

D)  

 

130 mA, from b to a

E)  

 

75 mA, from a to b

Ans D

Figure 29.3a

2)  

 
A long vertical wire carries a steady 10-A current. A pair of rails are horizontal and are apart.
A 20- resistor connects points a and b, at the end of the rails. A bar is in contact with the rails,
and is moved by an external force with a constant velocity of as shown.
The bar and the rails have negligible resistance. At a given instant
, the bar is from the wire, as shown. In Fig. 29.3a, at time t</span><sub>1, the induced current and its direction through
the resistor are closest to:  

 
2)  

 
_______

A)  

 

0.030 A, from b to a

B)  

 

0.18 A, from b to a

C)  

 

0.060 A, from a to b

D)  

 

0.060 A, from b to a

E)  

 

0.030 A, from a to b

Ans C

Figure 29.9

3)  

 
In Fig. 29.9, a bar magnet moves away from the solenoid.
The induced current through the resistor R is:  

 
3)  

 
_______

A)  

 
zero  

 
B)  

 
from a to b  

 
C)  

 
from b to a

Ans B

Figure 30.1a

4)  

 
An R</span><span class="Normal-0020Text--Char" style=" font-family: 'TestGen', 'Arial';
font-style: italic;">-</span><span class="Normal-0020Text--Char" style=" font-style: italic;
">L circuit has a 60-V battery, a 41-H inductor, a 25- resistor, and a switch S, in series, as shown. Initially, the switch is open, and
there is no magnetic flux in the inductor. At time the switch is closed.
In Fig. 30.1a, when the time the current in the circuit is closest
to:  

 
4)  

 
_______

A)  

 

1.1 A

B)  

 

1.3 A

C)  

 

0.88 A

D)  

 

1.9 A

E)  

 

2.4 A

Ans B

Figure 30.2b

5)  

 
An R</span><span class="Normal-0020Text--Char" style=" font-family: 'TestGen', 'Arial';
font-style: italic;">-</span><span class="Normal-0020Text--Char" style=" font-style: italic;
">L circuit is shown, with a 25- resistor and an ideal 46-H inductor, that has zero resistance. At time there is a
current in the circuit. In Fig. 30.2b, when the magnetic energy of the
inductor is 1600 J, the rate of dissipation in the resistor is closest
to:  

 
5)  

 
_______

A)  

 

1700 W

B)  

 

1300 W

C)  

 

870 W

D)  

 

2200 W

E)  

 

430 W

Ans A

Figure 30.4

6)  

 
A series circuit consists of an inductor, a capacitor, and
an open switch, with no appreciable resistance in the circuit. Initially
the switch is open with the capacitor fully charged. At time t = 0, the switch is suddenly closed. Which graph in Fig. 30.4
best represents the energy U stored in the inductor as a function of time?  

 
6)  

 
_______

A)  

 
1  

 
B)  

 
2  

 
C)  

 
3  

 
D)  

 
4  

 
E)  

 
5

Ans C

7)  

 
A  2.12 × Hz electromagnetic wave propagates in
carbon tetrachloride with a speed of The wavelength of the wave in
carbon tetrachloride is closest to:  

 
7)  

 
_______

A)  

 

1070 nm

B)  

 

1200 nm

C)  

 

1420 nm

D)  

 

1290 nm

E)  

 

967 nm

Ans E

8)  

 
A planar electromagnetic wave is propagating in the positive x</span><span
class="Normal-0020Text--Char" style=" font-family: 'TestGen', 'Arial';
">-</span>direction. At a certain point P and at a given instant, the electric field of the wave is
given by The magnetic vector of the wave, at the point P at that instant is closest to (i,j,k are unit vectors a