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WorksheetsTopic 17 - Electricity, Ohm's Law
Total questions: 41
Worksheet time: 21mins
Which electrical quantity has the same unit as electromotive force?
charge
current
potential difference
power
How could the unit of potential difference, the volt, also be written?
A/s
C/A
C/J
J/C
What is measured by the energy dissipated when a source drives a unit charge round a complete circuit?
electromotive force
potential difference
power
resistance
What is used in an electric circuit to allow current in one direction only?
a fuse
an ammeter
a diode
a relay
What is,the current İna 5.0 Ω resistor when the potential difference between the ends of the resistor is 2.5 V?
0.50 A
2.0 A
2.5 A
12.5 A
When a p.d, of 2 V is applied across a resistor, 10 J of energy are converted. What charge flows through the resistor?
0.20 C
5.0 C
12 C
20 C
A milliammeter shows a reading of 30 mA. How much electrical charge flows through the milliammeter in 10 seconds?
0.3 C
3.0 C
30 C
300 C
When a current of 2A flows for 5 seconds through a lamp, 120W of power are used. How much charge flows through the lamp?
10 C
12 C
24 C
60 C
What is measured by the energy dissipated when a source drives a unit charge round a complete circuit?
electromotive force
potential difference
power
resistance
Which of the following changes to a wire doubles its resistance?
A
B
C
D
Which of the following describes the e.m.f. of a cell?
the difference in energy between that needed to drive unit charge through the load resistors and through the cell
the energy used to drive unit charge through all the load resistors in the circuit
the energy used to drive unit charge through the resistance of the cell
the total energy used to drive unit charge round the complete circuit
A conductor carries a current of 2.0 A. How long does it take for 10 C of charge to pass one point in the conductor?
0.20 s
5.0 s
12 s
20 s
Materials can be classed, in electrical terms, as either conductors or insulators. Which two materials are correctly identified?
A
B
C
D
An electrical quantity is defined as 'the energy converted by a source in driving a unit charge around a complete circuit'. What is this quantity called?
current
electromotive force
potential difference
power
An electric lamp uses energy at the rate of 43 W on 12 V supply. How much charge passes through the lamp in 2 seconds?
0.25 C
0.50 С
2.0 C
8.0 C
A wire has a resistance of 8 Ω. A second wire, made of the same material, has half the length and twice the cross-sectional area. What is the resistance of the second wire?
1 Ω
2 Ω
8 Ω
16 Ω
A battery is used to light a 24 W electric lamp. The battery provides a charge of 120 C in 60 s. What is the potential difference across the lamp?
5 V
12 V
24 V
120 V
The amount of energy transferred when 10 C of charge passes through a p.d. of 20 V is the s as the energy needed to raise a 2 kg mass through a distance x. [gravitational field strength=10 N/kg]
What is the value of x?
0.1 m
1 m
10 m
100 m
Which diagram shows the V/I characteristic graph r a conductor that obeys Ohm's law?
A piece of wire 0.5 m long has an area of cross-section of 1 mm? What wire of the same material has twice the resistance?
A
B
C
D
A 0.4 m length of resistance wire with an area of cross-section of 0.2 mm, has a resistance of 2 Ω. Which wire of the same material will also have a resistance of 2 Ω?
A
B
C
D
Which circuit can be used to find the resistance of the lamp?
The potential difference (pd) between the ends of a conductor is 12 V. How much electrical energy is converted to other forms of energy in the conductor when 109 C of charge flows through it?
0.12 J
8.3 J
88 J
1200 J
Which circuit could be used to find the resistance of the resistor R?
Which variation would produce a graph of the shape shown?
count rate against time for a radioactive decay
current against potential difference for a metal obeying Ohm's law
pressure against volume for a gas at constant temperature
speed against time for a car moving at constant speed
The terminals of a battery are joined by a length Which change, on its own, will increase the current through the battery?
connecting an identical wire in series with the first one
covering the wire with plastic insulation
using a shorter wire of the same material and the same thickness
using a thinner wire of the same material and the same length
A 12 V lamp is connected to a 12 V supply using very long leads. Why does the lamp glow only dimly?
A d.c. supply is being used rather than an a.с. supply
Electrical energy is converted to heat in the long leads
The current through the lamp is less than that from the supply
The potential difference across each lead is half the voltage supply
Which graph best represents how current I varies with voltage V in a component in which the resistance decreases as the current increases?
The voltage-current graphs for four electrical devices are shown. Which graph shows the resistance increasing as the current increases?
A circuit is used to find the resistance of a coil of wire. Which diagram shows the correct positions for voltmeter and ammeter in the circuit?
The diagram shows an electric circuit. Which pair of readings is obtained when a suitable power supply is connected between X and Y?
A
B
C
D
A resistor with resistance R is made from a length L of resistance wire with a cross-sectional area A. A second resistor with resistance 2R is made from wire of the same material with a cross-sectional area of A/4. What length of wire is needed for the second resistor?
L/2
L
2L
8L
The graph shows the variation with voltage of the current in a 12 V lamp. From the graph which statement about the resistance of the lamp is correct as the voltage increases?
The resistance of the lamp decreases throughout the voltage range
The resistance of the lamp increases throughout the voltage range
The resistance of the lamp increases at first and then decreases
The resistance of the lamp remains constant
The diagram shows a circuit in which the ammeter reads 190 mA. Which voltmeter scale is best to measure the potential difference across the resistor?
A wire of length 1.0 m has a resistance of 200 Ω. When connected to a cell, the current in the wire is 3.0 A.
A
B
C
D
A 1.0 Ω resistor and a 2.0 Ω resistor are connected in series across a 12 V d.c. supply. What is the current in the circuit?
0.25 A
4.0 A
6.0 A
12 A
A 12Ω resistor is connected across an 8.0 V supply as shown. What is the power produced in the resistor?
0.67 W
1.5 W
5.3 W
770 W
The terminals of a battery are joined by a length of resistance wire. Which change increases the current in the battery?
connecting an identical wire in series with the first one
increasing the temperature of the wire
using a shorter wire of the same material and same thickness
using a thinner wire of the same material and the same length
Which circuit can be used in an experiment to find how the current through a diode varies with potential difference?
Voltage-current readings were obtained for different electrical components. Which reading are for a 3 V, 0.06 A torch lamp?
A
B
C
D
X and Y are lamps with filaments made of the same material. The filament of lamp X is thicker and shorter than that of lamp Y. Each lamp is connected to the mains and switched on. Which is the brighter lamp and which lamp has larger resistance?
A
B
C
D
