Post on 04-Jun-2018
For each of the questions, there are four possible
choices. Choose the one you consider correct andrecord your choice.
U l. What is electrical current?
A rate ofchange ofvoltageB rate ofchange ofresistanceC rate offlow ofchargeD rate of flow of power
t\,g 6V5. How much charge
flows through theresistor in 4 s?
A 3Cc t2c
3
())
t\,0
t\,0
2. What is meant by 5 A?
A 5 C of charge flows through a point in Isecond.
B 5 V ofelectricity across I Cl ofresistance.C 5 V of electricity causing lC of charge to
flow.D 5 C of charge flowing through a point.
()
3. Which of the following is true about point P?
6V3A
2A
2R
A Current is flowing in direction 4.
B Electron is flowing in direction 4.
C Electron is flowing in either direction 1 ordirection 3.
D Electron is flowing in direction 2. ( )
4. Which is a unit of current?
AQV BVRC Cs-' D CV
IVg 6. If 50 C of charge flows through a point inan electric circuit in 10 s, what is the currentpassing through that point?
A O.2A B 5,Ac60A Ds00A ( )
U 7 . Acell containing 1200 C of charge is connected
to a circuit. What is the time taken to discharge
the cell given that the current of the circuit is
6A?
A 0.005 h B 200 h
C 200s D 7200s ( )
U 8. There is 100 C of charge stored in a cell. Giventhat 5OVo of the charge flows out of the cell inl0 s, what is the average rate of flow of charge
out of the cell?
A O.IA B O.5Ac sA D tOA ( )
\\,0 q. Electromotive force is defined as
A the work done by an appliance in drivingelectrons round a circuit.
B the work done by a source in driving a unitcharge round a circuit.
C the work done to drive a unit charge througha component.
D the product ofcurrent and resistance.
()
2
Mg
93 Unit 16 Cunent of Electricity and D.C. Circuits
Gurrent of Electricity andand
Magnetism
B 6CD I8C
Theme 5
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Nu, A resistance wire AB is connected in a circuitas shown. What happens to the brightness of the
lamps as the jockey slides along the resistance
wire from point A to point B?
A B
5C) 5c)
10c,
LampP LampQ
A Lamp P gets brighter while lamp Q gets
dimmer.
B Lamp Q gets brighter while lamp P gets
dimmer.
C There is no change in the brightness of lamp
P and lamp Q.D Both lamp P and lamp Q do not light up.
()
Extension Questions
WOr. *nu, is the effective resistance of the nine
resistors?
2012
A 5clC 15Q
B 10c)D 2OQ (
20f2
10c)
10Q l0o
10c)
U ur. *nu, is the value of current 1,?
t2Y
A IAC4A
t2v
A 1AC 4A
lo
2Q
2A
20
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()
3
Il
U *. *u, is the value of current 1,?
t2v
l.0A2.0 A
4Q
B3AD 12A
4A
B3AD6A
4Q
20B 1.5AD 3.OA
4
Il
Vur. *nu, is the value of current /,?
It
AC )
l0l Unit 16 Current of Electricity and D.C. Circuits
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Vu,
Vut
66. Which of the following produce(s) directcurrent?
I
time
e.m.f.
2
4J
timetime
A resistor can be added to the circuit below tomake the current 1= 3A'. Which is it?
t2v
A 4 onlyB 3and4onlyC 2,3 and 4 onlyD 1,2 and 3 only
A 2QC 6cl
A2AC lOQ
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)
A resistor can be added to the circuit below tomake the current 1= 3A. Which is it?
t2v
B 4c)D 8C)
B 6C)D 12Q (
69. The circuit diagram shows four identicalresistors connected in a series with a battery.
What are the possible readings on voltmeters
V, and Vr?
2A 4A
U
102 Unit 16 Current of Electricity and D.C. Circuits
I
vr
A IVB2YC 3VD 4V
12A
A 3AC6A
Y2
3V8V6V6V
B4AD8A ()
)
IMg 70. A student wants to know the resistance of a
conductor when a current 1 = 0.50 A flowsthrough it. How can he obtain the result?
A By calculating the gradient of a V-I graph.
B By calculating the gradient of a I-V graph.
C By calculating the gradient of a V-I graph
at 1= 0.50 A.D Obtain the corresponding p.d. V across the
conductor when 1= 0.50 A. Then calculate
resistance uring ;}. ( )- 0.50
U 7l . Which of the following statements is correct?
I2
=1:and Ir=lr+lr.is smaller than 1, but bigger than I r.is greater than 1, but smaller than /,.is greater than Irbut smaller than 1r.
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U rr. *nu, is the value of current /?
ll
AI,B1,CI,D1,
lo
2A
6O
3C,
I
(
I
)
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V,, In the flgure below, AB is a 2 m long resistance
wire. When AC = 1.6 m, the galvanometer
indicates a zero reading.
1.6 m+------------------)
C
What is the resistance of R?
46C, B IzC)c 24d, D 30O ()
U 74.Three resistors, each of resistance 6 C), are
arranged to give a 9 C2 combination across PQ.
Which of the following is the arrangement?
A
P
BP
C
P
D
P
o
o
a)
U
U
75. In an experiment, four resistance wires made
from the same material are connected in turn
between the terminals P and Q in the circuitshown. The length and diameter of the wires
are different.
PQ
Which wire will give the smallest reading on
the ammeter?
Length Diameter
A 0.5 m 0.5 mm
B 0.5 m 0.05 mm
C 5.0 m 0.5 mm
D 5.0m 0.05mm ( )
76. What happens to the brightness of the lamp
when the switch is closed?
A It becomes dimmer.
becomes brighter.goes off.remains the same.
BItCItDIt
\\,s
A 0.17Ac 0.67 A
B 0.33 AD 1.00,4
(
()
77. Six 6 C) resistors are connected to a 6 V cell ofnegligible internal resistance as shown below.
What is the current that flows through pointP?
P
6c) 6O
\o
6C) 6Q
103 Unit 16 Current of Electricity and D.C. Circuits
6C,R
(
6O
6Q
6O
6O 6c) 6O
6C, 6C,
6C,
6C)
6c, 6C2
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6O
€d
€
6o
V,,
\\,s
MCI
Five 6 O resistors are connected to a 6 V cell ofnegligible internal resistance as shown below.
What is the current that flows through pointP?
P
A 0.20 Ac 0.50 A ()
79. In the circuit shown below, the ammeter reads
0.50Awhen S, is closed and S, is opened. Whatwould the ammeter reading be if both S, and S,are closed?
6V
B 0.25 AD 1.25 A
B 0.75 AD 3.00A
sr
A 0.67 Ac 1.33 A (
80. In the figure below, lamp P has twice the
resistance of lamp Q.The relationship between
the current 1 and current 1 ispq
PIP
B 2l =lpqD I =41pq
A 4I =lpqCI=21
Pq )
IVCI
i\,g
81. Which of the following graphs shows therelationship between the resistance R of a wire,and its cross-sectional area A?
R R/Q B
Al mmz A/ mmz
OA
RIA C RI D
Al mm2 Almmz
()
82. Which of the following statements is correctfor the circuit shown below?
A The bulb becomes brighter when therheostat is adjusted to a higher resistance
because as the resistance increases, thepotential difference increases.
B The bulb becomes dimmer when the rheostat
is adjusted to a higher resistance because
as the resistance decreases, the potential
difference decreases.
C The brightness of the bulb cannot be
adjusted because the potential differenceacross the bulb is constant.
D The brightness of the bulb cannot be
adjusted because its resistance is constant.()
104 Unit 16 Current of Electricity and D.C. Circuits
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6C)
3Q
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83. Acircuit is connected as shown in the diagram.
Given that the three resistors are identical,which of the following statements are true?
I A, has the highest reading.
2 Ar, A, and A, have the same reading.
3 Reading of A, is greater than Au.
A land2onlyC 2and3only
B land3onlyD 1,2 and3 (
84. Resistors R, and R, are connected in a circuitas shown below. When switch S is opened, the
ammeter reads 1.5 A and the voltmeter reads
9 V. When switch S is closed, the ammeter
reads 3.0 A and the voltmeter reads 6 V.
S
What are the resistances of R, and Rr?
R,/Q Rr/C2
A3 6
B6 3
c4 8
D8 4 ( )
\V0r85. In the circuit below, the three lamps are
identical. When switch S is closed,
P
R
Vru
S
A lamp P becomes dimmer.
B lamp P is as bright as lamp Q.C lamp P is not as bright as lamp R.
D lamp Premains as bright as when switch S
is opened. ( )
A heater is connected to the 12 V battery as
shown in the diagram.
t2v
1A
heater
The fan with a resistance of R has a p.d. of6 V across it and a current of I A through it.The bulb has a current of 2 A flowing thoughit. Which of the following is true?
A The voltage across the bulb is 6 V and its
resistance is 2R.
B The voltage across the bulb is 6 V and its
resistance is 1n.2
C The voltage across the bulb is 3 V and its
resistance is 2R.
D The voltage across the bulb is 3 V and its
resistance i, 1R. ( )2
105 Unit 16 Current of Electricity and D.C. Circuits
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v
U,,
Two wires P and Q, each of the same lengthand the same material are connected in parallel
to a cell. The diameter of P is half the diameter
of Q. What fraction of the total current passes
through P?
Bl4
D12
A15
c1J
88. Four resistors are connected as shown in the
diagram.
P 3C)
6c, 6C,
S3C)
Which 2 points when connected to terminalsX and Y in the following circuit will give the
highest reading on the ammeter?
x
A PandQC RandQ
A IOC2
c 1200
B QandSD SandP
B 24f2D 600c)
()
)
()
Y
A heater produces 2.4 kW when a 240 voltsmains supply is connected across it. What isthe resistance of the heater?
Uro.
V,
v2lYOV3Vt2YOV
One of the four identical light bulbs in a series
circuit has blown off as shown. What will be
the voltage readings VrandVr?
t2Y
open circuit
1. Calculate the resistance of the resistor labelledR.
2A
vtlYA 0vB 3VC OVD 3V
A 2AC 6Cl
B 4QD 8Q
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)
t2f2
4Q
R
106 Unit 16 Cunent of Electricity and D.C. Circuits
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