# Which one of the following is a correct definition of electric potential

```Which one of the following is a correct definition of
electric potential difference between two points?
A.
The power to move a small positive charge
between the two points.
B.
The work done to move a small positive charge
between the two points.
C.
The power per unit charge to move a small
positive charge between the two points.
D.
The work done per unit charge to move a small
positive charge between the two points.
The unit, the electron-volt is
equivalent to
A.
B.
C.
D.
1.6 &times; 1019 J.
1.0 J.
1.6 &times; 10–19 J.
9.1 &times; 10–31 J.
An electron and a proton are accelerated
from rest through potential differences of
the same magnitude. After acceleration
the speed of the electron is ve and the
speed of the proton is vp. Which of the
following is the best estimate for the ratio
vp/ve?
A. 2000
C. (2000)-0.5
B. (2000)0.5
D. 1/2000
A proton and an alpha particle are accelerated from
rest from the positively charged plate X to the
negatively charged plate Y.
+
+
+
+
proton
+
+
X
alpha particle
mid-point
–
–
–
–
–
–
Y
At the mid-point between the plates, the proton has a
kinetic energy EK. At this point, the alpha particle has
a kinetic energy
A. EK/2 .
B.
EK.
C. 2EK.
D.
4EK
Which one of the following units is a
unit of energy?
A.
B.
C.
D.
eV
W s–1
W m–1
N m s–1
A proton of mass m and charge e is
accelerated from rest through a
potential difference V. The final speed
of the proton is
A.
B.
C.
D.
(2Ve/m)0.5
2ve/m
(Ve/m)0.5
D. Ve/m
The graph
shows the I–V
characteristics
of two
resistors.
When resistors X and Y are connected in series, the
current in the resistors is 2.0 A. What is the resistance
of the series combination of X and Y?
A.
7.0 Ω
B. 1.3 Ω
C. 1.1 Ω
D. 0.14 Ω
Which one of the following lists a
fundamental unit and a derived unit?
A. Ampere, second
B. Coulomb, kilogram
C. Coulomb, newton
D. Metre, kilogram
Two resistors, of resistance R1 and R2, are
connected in series with a cell of emf ε and negligible
internal resistance.
Which expression gives the potential difference
across the resistor of resistance R1?
A.
B.
 R1

 R1  R 2



C.  R1  R2 
 R1  R 2

 R1



D.  R2


R2





 R1  R 2 
Which one of the following
measurements is stated correctly
to two significant digits?
A.
B.
C.
D.
0.006 m
0.06 m
600 m
620 m
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.
C. 24 W.
B. 12 W.
D. 48 W.
The resistive force F acting on a sphere of
radius r moving at speed v through a liquid
is given by
F = cvr
where c is a constant. Which of the
following is a correct unit for c?
A.
C.
N
N m2 s–1
B.
D.
N s–1
N m–2 s
The current in the circuit shown below is constant when the
switch is closed. The energy transfer in the internal
resistance r of the battery is 15 J when a charge of 40 C
passes through it. For the same amount of charge, 45 J of
energy is transferred in the resistor R.
r
R
Which of the following gives the emf of the battery?
A. 15
C. 45
V
V
40
40
B. 30
V
40
D. 60
V
40
Gillian carried out an experiment to investigate the craters formed when steel
balls are dropped into sand. To try and find the relationship between the
diameter of the crater and the energy of impact of steel balls of the same
diameter, she dropped a steel ball from different heights h into sand and
measured the resulting diameter d of the crater. The data are shown plotted
below.
The original hypothesis, made by Gillian, was that the diameter of the crater
is directly proportional to the energy of impact of the steel balls. Explain why
the data does not support this hypothesis.
The graph below shows the variation with current I of
the potential difference V across a filament lamp.
V / volts
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0.0
0.5
1.0
1.5
2.0
I / mA
The resistance of the lamp when I = 1.5 mA is
A. 950 W.
B. 400 W.
C. 0.95 W.
D.0.40 W.
Three identical electrical heaters each provide
power P when connected separately to a supply S
which has zero internal resistance. On the
diagram below, complete the circuit by drawing
two switches so that the power provided by the
heaters may be either P or 2P or 3P.
The graph below shows the I-V (current-voltage) characteristic
of an electrical component T.
On the graph, draw the I-V characteristic in the range V = 0 to
V = 6.0V for a resistor R having a constant resistance of 40Ω.
150
100
I / mA
50
0
0.0
2.0
4.0
V/V
6.0
8.0
Which of the following is the best
estimate, to one significant digit, of
the quantity:
π  8.1
?
15.9
A.
B.
C.
D.
1.5
2.0
5.8
6.0
A battery of internal resistance 2 Ω is connected to an
external resistance of 10 Ω. The current is 0.5 A.
What is the emf of the battery?
A.
1.0 V
B.
5.0 V
C.
6.0 V
D.
24.0 V
The electromotive force (emf) of a cell is defined
as
A. the power supplied by the cell per unit
current from the cell.
B. the force that the cell provides to drive
electrons round a circuit.
C. the energy supplied by the cell per unit
current from the cell.
D. the potential difference across the
terminals of the cell.
A resistor of resistance 12 Ω is connected
in series with a cell of negligible internal
resistance. The power dissipated in the
resistor is P. The resistor is replaced with a
resistor of resistance 3.0 Ω. What is the
power dissipated in this resistor?
A.
B.
C.
D.
0.25 P
P
2.0 P
4.0 P
Two rectangular blocks, X and Y, of the same material
have different dimensions but the same overall
resistance. Which of the following equations is
correct?
```