IB PHYSICS HL
MULTIPLE CHOICE REVIEW
ELECTRIC CIRCUITS
1.
A heater has a resistance R when the potential difference across it is 12 V. In the circuit below, it is
connected in series with a 36 V supply and a resistor S.
36 V
S
To ensure that the potential difference across the heater is 12 V, the resistance of the resistor S should be
A.
R
.
2
B.
2R
.
3
C.
3R
.
2
D.
2R.
(1)
2.
In the circuit shown, the voltmeter has a resistance of 20 kΩ and the battery has an emf of 6.0 V and
negligible internal resistance.
6.0 V
10 k
20 k
V
20 k
The reading on the voltmeter is
A.
2.0 V.
B.
3.0 V.
C.
4.0 V.
D.
6.0 V.
(1)
3.
In which one of the circuits below is it possible to vary the current in the lamp by adjusting the variable
resistor? The cell has negligible internal resistance.
1
A.
B.
C.
D.
(1)
4.
Two filament lamps X and Y are designed to operate at normal brightness when the potential difference
across the lamps is 6 V. Each lamp will just light when the potential difference across it is 3 V.
The two lamps are connected in parallel to a 4 V supply of negligible internal resistance as shown below.
4V
X
Y
The filament of lamp X breaks so that there is no current in it. The filament of lamp Y will
A.
glow at normal brightness.
B.
glow at more than normal brightness.
C.
glow more dimly.
D.
stay at the same brightness.
(1)
2
5.
Three identical resistors of constant resistance are connected in series to a battery of negligible internal
resistance. The total power dissipated in the circuit is P.
The three resistors are now connected in parallel. The total power dissipated is
A.
P
.
3
B.
P.
C.
3P.
D.
9P.
(1)
6.
Three networks X, Y and Z are shown below. Each resistor has the same resistance.
Z
Y
X
Which list shows the network resistances in increasing order of magnitude?
least → greatest
A.
X
Y
Z
B.
Y
X
Z
C.
Y
Z
X
D.
Z
X
Y
(1)
7.
In the circuit below, which meter is not correctly connected?
A
1
V
A
3
2
V
A.
1
B.
2
C.
3
D.
4
4
(1)
3
8.
In the circuit below, n charge carriers pass the point P in a time t. Each charge carrier has charge q.
P
The current in the circuit is given by the expression
A.
q
.
t
B.
nq
.
t
C.
qt
.
n
D.
nqt.
(1)
9.
The element of an electric heater has a resistance R when in operation. What is the resistance of a second
heater that has a power output three times as large at the same operating voltage?
A.
R
9
B.
R
3
C.
3R
D.
9R
(1)
10.
The graph below shows the variation with potential difference V of the current I in an electrical
component.
I
0
0
V0
V
Which one of the following is a correct statement about the resistance of the component?
A.
For potential differences greater than V0, the resistance is constant.
B.
For potential differences greater than V0, the resistance decreases with increasing potential
difference.
C.
The variation of current with potential difference is linear and so Ohm’s law is obeyed.
D.
For potential differences less than V0, the resistance is zero.
(1)
4
11.
The resistors in each of the circuits shown below each have the same resistance.
circuit P
circuit Q
circuit S
Which of the following gives the circuits in order of increasing total resistance?
A.
P
Q
S
B.
Q
P
S
C.
S
Q
P
D.
P
S
Q
(1
12.
A resistor of resistance 1.0  is connected in series with a battery. The current in the circuit is 2.0 A.
The resistor is now replaced by a resistor of resistance of 4.0 . The current in this circuit is 1.0 A.
A
2.0 A
1.0 
4.0 
The best estimate for the internal resistance of the battery is
A.
1.0 .
B.
2.0 .
C.
4.0 .
D.
5.0 .
(1)
13.
A conductor of constant resistance dissipates 6.0 W of power when the potential difference across it is 12
V. The power that will be dissipated in this conductor when the potential difference across it is 24 V is
A.
6.0 W.
B.
12 W.
C.
24 W.
D.
48 W.
(1)
5
14.
A voltmeter of resistance 50 k is connected in a circuit as shown in the diagram below.
e.m.f. = 12V
V
50k
R
10k
The emf of the battery is 12 V and the resistance of the resistor is 10 k. The internal resistance of the
battery is negligible.
The reading of the voltmeter is
A.
0.0 V.
B.
2.0 V.
C.
10 V.
D.
12 V.
(1)
15.
The circuit contains a battery of e.m.f. 12 V and negligible resistance.
25Ω
12V
15Ω
What is the potential difference across the 25 Ω resistor?
A.
3.0 V
B.
4.5 V
C.
5.0 V
D.
7.5 V
(1)
16.
In the circuit shown below, the cell has negligible internal resistance.
Which of the following equations is correct?
A.
I1 = 2I2
B.
I1 = 2I3
C.
I2 = 2I3
D.
I3 = 2I1
(1)
6
MARK SCHEME!
1.
D
[1]
2.
B
[1]
3.
A
[1]
4.
D
[1]
5..
D
[1]
6.
B
[1]
7.
D
[1]
8.
B
[1]
9.
B
[1]
10.
B
[1]
11.
B
[1]
12.
B
[1]
13.
C
[1]
14.
C
[1]
15.
D
[1]
16.
C
[1]
7