KING SAUD UNIVERSITY
PHYSICS & ASTRONOMY DEPARTMENT
106-Phys (Dr. ABDALLAH M. AZZEER)
MCQ – Chapter 17
WRITE YOUR ANSWER ON THE ATTACHED SHEET
1. An accelerator produces beams of positive He ions with charge +2e (e = 1.6 x 10-19 C)
moving at a velocity v. The cross sectional area of the beam is A and the current is I.
The number of He ions per unit volume in the beam is
(a) I/Av
(b) I/2eAv
(c) I/eAv
(d) 2I/eAv
2. Two copper wires carry equal currents, but wire 2 has twice the radius of wire 1. The
ratio of drift velocities v2/v1 is
(a) 1
(b) 2
(c) 1/2
(d) 1/4
3. A copper wire has a resistance of 8 Ω. A second copper wire is twice as long and has
half the diameter. Its resistance is
(a) 1 Ω
(b) 8 Ω
(c) 32 Ω
(d) 64 Ω
4. A nerve fiber has a resistivity of 2 Ω m. It is approximately a cylinder of length 0.4 m
and cross sectional area 10-9 m2. What is its resistance?
(a) 5 × 109 Ω
(b) 8 × 108 Ω
(c) 1.25 × 10-9 Ω
(d) 5 × 10-9 Ω
5. A wire of length L and radius r has a resistance R. What is its resistivity?
(a) R/r2 L
(b) πr2 R/L
(c) R/πr2 L
(d) πr2 LR
6. A 10 Ω resistance is connected to a 6 V battery that has an internal resistance of 2
ohms. Find the current.
(a) 0.5 A
(b) 0.6 A
(c) 0.75 A
(d) 1.25 A
7. A storage battery has a 12 V EMF and a 0.1 Ω internal resistance. A battery charger
is charging it at the rate of 10 A. What is the terminal voltage of the battery?
(a) 0 V
(b) 10 V
(c) 12 V
(d) 13 V
8. The three resistors shown have an equivalent resistance of
(a) 3 ohms
6Ω
6Ω
6Ω
(b) 6 ohms
(c) 12 ohms
(d) 18 ohms
9. The four resistors shown have an equivalent resistance of
(a) 3 ohms
(b) 4 ohms
(c) 6 ohms
(d) 12 ohms
12 Ω
12 Ω
12 Ω
12 Ω
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Dr. Abdallah M. Azzeer
10. The equivalent resistance of these resistors for current entering at A and leaving at B
is
4Ω
(a) 4/3 Ω
4Ω
A
(b) 2 Ω
B
(c) 6 Ω
4Ω
(d) 8 Ω
11. For currents entering at A and leaving at B, the equivalent resistance of this network
is 7 Ω. What is R?
(a)
(b)
(c)
(d)
2Ω
4Ω
6Ω
8Ω
3Ω
R
A
B
4Ω
12. A battery (not shown) is connected to points A and B. The voltage drop across the 4
ohm resistor is 10 V. What is the voltage drop across the 2 ohm resistor?
(a) 2 V
2Ω
4Ω
(b) 5 V
A
B
(c) 10 V
(d) 15 V
13. A 24 A current enters at point A and leaves at point B. How large is the current in the
12 ohm resistor?
4Ω
(a) 8 A
(b) 12 A
A
B
(c) 16 A
(d) 18 A
12 Ω
14. Four identical resistors are connected in series to a 6 V battery. What is the voltage
drop across one resistor?
(a) 0
(b) 1.5 V
(c) 6 V
(d) 12 V
15. A 2 ohm and a 4 ohm resistor are connected in series to a 12 V battery, What is the
voltage drop across the 2 ohm resistor?
(a) 2 V
(b) 4 V
(c) 6 V
(d) 8 V
16. A 6 ohm and a 12 ohm resistor are connected in parallel to a 12 V battery. What is
the current in the battery?
(a) 0.67 A
(b) 1 A
(c) 3 A
(d) 4 A
17. Which equation is correct? (The units have been omitted.)
I1
(a) 2I1+10-17-3I2= 0
(b) 2I1+10-17+3I2= 0
I2
2Ω
10 V
3Ω
17 V
4Ω
4V
(c) 2I1+10+17-3I2= 0
(d) 2I1+10+17+3I2= 0
Page 2 of 6 - CH17
I3
Dr. Abdallah M. Azzeer
I1
18. Which equation is correct?
(a) I1+I2+I3=0
I2
(b) I1-I2-I3=0
2Ω
10 V
3Ω
17 V
4Ω
4V
(c) I1-I2+I3=0
(d) I1+I2-I3=0
I3
19. The current through the 4 ‫ ظ‬resistor of the adjacent circuit is:
6Ω
(a) 0.92 A
(b) 2 A
4Ω
(c) 3 A
3Ω
(d) 6 A
12 V
20. The equivalent resistance between points a and b in the figure is:
5Ω
(a) 13 ohm
4Ω
(b) 15 ohm
(c) 19 ohm
b
(d) 7.6 ohm
(b) 3 V and 13 V
3Ω
6Ω
E1
f
21. In the circuit shown, E1 and E2 are respectively:
(a) 5 V and 5 V
1Ω
a
e
1A
1Ω
2A
d
c
2Ω
I
(c) 5 V and 3 V
(d) 7 V and 3 V
22. The value of ‫ﻩ‬1 in the circuit is:
(a) 13 V
(b) 15 V
(c) 18 V
(d) 22 V
a
b
3Ω
20 V
a
1A r
I
f s
2A r
E2
7Ω
b
ε1
5Ω
ε2
c
3Ω
e
23. The potential difference between the point's b
and d for the circuit in 22 is:
(a) 27 V
(b) 20 V
(c) 17.5 V
Page 3 of 6 - CH17
d
(d) 13 V
Dr. Abdallah M. Azzeer
24. In the circuit shown, E1 and E2 are respectively:
(a) 3 V and 13 V
(b) 5 V and 3 V
E1
f
e
1A
1
2A
d
c
(c) 7 V and 13 V
I
(d) 3 V and 5 V
2
a
b
3
25. For the circuit shown in the figure. The current I2 is:
6V
(a) 1.08 A
I2
(b) 1.68 A
(c) 22.5 mA
E2
1.5 Ω
(d) 285 mA
1Ω
1Ω
1Ω
26. Two resistors with different resistances are connected in parallel with a battery.
Which statement is TRUE?
(a) The voltage drop across each is the same.
(b) The voltage drop across the two is the sum of the voltage drops.
(c) The equivalent resistance is the sum of their resistances.
(d) The current through each is the same.
27. According to Kirchhoff's rules, the
(a) current entering a point is more than the current leaving
(b) algebraic sum of the voltage drops around a closed loop is positive
(c) algebraic sum of the voltage drops around a closed loop is negative
(d) algebraic sum of the voltage drops around a closed loop is zero
28. If there are n points where currents branch and m small loops, Kirchhoff's rules give
(a) n + m independent equations
(b) n + m - 1 independent equations
(c) n + m + 1 independent equations
(d) n + m - 2 independent equations
29. How many independent equations does Kirchhoff's first rule give for this circuit?
2Ω
10 V
3Ω
20 V
(a) 0
(b) 1
(c) 2
(d) 3
10 Ω
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Dr. Abdallah M. Azzeer
30. How many independent equations does Kirchhoff's second rule give for the circuit in
Q29?
(a) 0
(b) 1
(c) 2
(d) 3
31. How many independent equations does Kirchhoff's second rule give for this circuit?
(a) 0
2Ω
10 V
3Ω
20 V
(b) 1
(c) 2
(d) 3
5Ω
5V
10 Ω
Additional Problems
R
If the equivalent resistance of the circuit, shown in the figure, is 10 ohm. Calculate;
(a) Resistance R
R
(b) The current that passes through R/2.
a
b
(c) The voltage difference between points a and b.
R/2
ANS; (a) 12 Ω, (b) 1.2 A, (c) 4.8 V
R
12 V
Page 5 of 6 - CH17
Dr. Abdallah M. Azzeer
KING SAUD UNIVERSITY
PHYSICS & ASTRONOMY DEPARTMENT
106-Phys (Dr. ABDALLAH M. AZZEER)
WRITE YOUR ANSWER ON THE ATTACHED SHEET
. . . . . . . . :‫اﻟﺮﻗﻢ اﻟﺠﺎﻣﻌﻲ‬
ANSWER SHEET
. . . . . . . . . . . . . . . . . . . . . . :‫اﻻﺳــﻢ‬
1.
13.
25.
2.
14.
26.
3.
15.
27.
4.
16.
28.
5.
17.
29.
6.
18.
30.
7.
19.
31
8.
20.
The more problems you do,
the more chance to get A+
9.
21.
The more problems you do,
the more chance to get A+
10.
22.
The more problems you do,
the more chance to get A+
11.
23.
The more problems you do,
the more chance to get A+
Page 6 of 6 - CH17
Dr. Abdallah M. Azzeer
12.
Page 7 of 6 - CH17
24.
The more problems you do,
the more chance to get A+
Dr. Abdallah M. Azzeer