Download Electricity Revision Exam Questions - SJHS-IB

IB
Physics
Electricity Revision Exam Questions
1.
In the circuit below, the voltmeter has a resistance 100 k. The battery has negligible internal
resistance and emf 6 V.
The reading on the voltmeter is
A. 0 V.
B. 2 V.
C. 3 V.
D. 4 V.
2.
(1)
Which graph best represents the relationship between the current I and the voltage V of a
filament lamp.
A.
0
0
C.
B.
V
0
0
0
0
I
D.
V
I
V
I
V
0
0
I
(1)
1
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3.
Physics
Three resistors P, Q and R, are each labelled 100 Ω. They are connected as shown.
X
Q
R
P
Y
The total resistance, when measured between points X and Y, is found to be 200 Ω.
What is the correct explanation for the resistance reading?
A.
Resistor R is zero
B.
Resistor R is infinite
C.
Resistor P is zero
D.
Resistor P is infinite
(1)
4.
The work done on a positive point charge of magnitude 3.0 nC as it is moved at constant speed
from one point to another is 12 nJ. The potential difference between the two points is
A.
0.0 V.
B.
0.25 V.
C.
4.0 V.
D.
36 V.
(1)
5.
In the circuit below, resistors X, Y and Z are connected in series with a 9.0 V supply.
+9.0 V
0
3000 
X
3000 
Y
Z
V
Resistors X and Z are fixed resistors of resistance 3000 . The resistance of resistor Y may be
varied between zero and 3000 .
Which of the following gives the maximum range of potential difference V across the resistors
X and Y?
A.
0 to 6.0 V
B.
3.0 V to 6.0 V
C.
4.5 V to 6.0 V
D.
4.5 V to 9.0 V
(1)
2
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6.
Physics
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)
7.
In the circuit below the battery has emf 6.0 V and negligible internal resistance. The three
resistors each have resistance 10 . A high resistance voltmeter is connected as shown.
6.0 V
10
10
10
V
The reading of the voltmeter is
A.
2.0 V.
B.
3.0 V.
C.
4.0 V.
D.
6.0 V.
(1)
3
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8.
Physics
In the circuit below, the battery has negligible internal resistance. Lamps L, M and N which
have different resistance are connected as shown.
L
M
N
Which one of the following is always true?
A.
Lamps L and N have the same current through them.
B.
Lamps L and M have the same current through them.
C.
Lamps L and N have the same potential difference across them.
D.
Lamps L and M have the same potential difference across them.
(1)
9.
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)
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10.
Physics
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)
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)
5
IB
12.
Physics
This question is about electrical resistance.
(a)
Define electrical resistance.
...................................................................................................................................
...................................................................................................................................
(1)
(b)
(i)
Three resistors, each of resistance 6.0 , are connected as shown below.
6.0
6.0
A
6.0
B
Calculate the total resistance between point A and point B of this arrangement.
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(1)
(ii)
The arrangement in (b)(i) is now connected to two more resistors, as shown below.
Each resistor is of resistance 6.0 .
6.0
6.0
6.0
A
6.0
B
C
6.0
D
Using your answer in (b)(i), deduce that the total resistance between point C and
point D is 8.4 .
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(iii)
One of the resistors in the arrangement shown in (b)(ii) becomes faulty. The
resistance between point C and point D is found to be 6.0 . On the diagram in
(b)(ii) above, identify the faulty resistor by drawing a circle around it. Deduce the
nature of the fault.
.........................................................................................................................
(2)
(Total 6 marks)
6
IB
13.
Physics
This question is about an electric circuit
A particular filament lamp is rated at 12 V, 6.0 mA. It just lights when the potential difference
across the filament is 6.0 V.
A student sets up an electric circuit to measure the I-V characteristics of the filament lamp.
In the circuit, shown below, the student has connected the voltmeter and the ammeter into the
circuit incorrectly.
A
100 k
S
12V
V
The battery has emf 12 V and negligible internal resistance. The ammeter has negligible
resistance and the resistance of the voltmeter is 100 k.
The maximum resistance of the variable resistor is 15 .
(a)
Explain, without doing any calculations, whether there is a position of the slider S at
which the lamp will be lit.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(3)
(b)
Estimate the maximum reading of the ammeter.
...................................................................................................................................
...................................................................................................................................
(2)
(c)
Complete the circuit diagram below showing the correct position of the voltmeter and of
the ammeter in order to determine the I-V characteristics of the filament lamp.
12V
(2)
(Total 7 marks)
7
IB
14.
Physics
Electric circuits
(a)
The diagram below shows the circuit used to measure the current-voltage (I-V)
characteristic of an electrical component X.
X
On the diagram above,
(i)
label the ammeter A and the voltmeter V.
(1)
(ii)
mark the position of the contact of the potentiometer that will produce a reading of
zero on the voltmeter. Label this position P.
(1)
(b)
The graph below shows the current-voltage (I-V) characteristics of two different
conductors X and Y.
0.50
0.45
0.40
0.35
0.30
I /A
Y
X
0.25
0.20
0.15
0.10
0.05
0.00
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0 10.0 11.0 12.0 13.0 14.0 15.0
V/V
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IB
Physics
(i)
State the value of the current for which the resistance of X is the same as the
resistance of Y and determine the value of this resistance
Current:
.....................................................................................................
Resistance: .....................................................................................................
(2)
(ii)
Describe and suggest an explanation for the I-V characteristic of conductor Y.
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(3)
(c)
The two conductors X and Y are connected in series with a cell of negligible internal
resistance. The current in the conductors is 0.20 A.
Use the graph in (b) to determine
(i)
the resistance of Y for this value of current;
.........................................................................................................................
.........................................................................................................................
(1)
(ii)
the emf of the cell.
.........................................................................................................................
.........................................................................................................................
(2)
(Total 10 marks)
9
IB
15.
Physics
This question is about electric circuits.
(a)
(i)
Define emf and state Ohm’s law.
emf: ....................................................................................................
....................................................................................................
Ohm’s law: ....................................................................................................
....................................................................................................
(2)
(ii)
The graph below shows the I-V characteristic of a particular electrical component.
V
0
0
I
State show the resistance of the component is determined from the graph.
.........................................................................................................................
.........................................................................................................................
(1)
(b)
In the circuit below an electrical device (load) is connected in series with a cell of emf 2.5
V and internal resistance r. The current I in the circuit is 0.10 A.
e.m.f. = 2.5V
r
I = 0.10A
load
The power dissipated in the load is 0.23 W.
10
IB
Physics
Calculate
(i)
the total power of the cell;
.........................................................................................................................
.........................................................................................................................
(1)
(ii)
the resistance of the load;
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(iii)
the internal resistance r of the cell.
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
.........................................................................................................................
(2)
(c)
A second identical cell is connected into the circuit in (b) as shown below.
I = 0.15A
load
The current in this circuit is 0.15 A. Deduce that the load is a non-ohmic device.
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
...................................................................................................................................
(4)
(Total 12 marks)
11