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Content
9.3 TRANSISTOR
1. Question 4: Kedah 07
Diagram 4.1 shows the use of a transistor in
a circuit.
........................................................
[1 mark]
2. Question 6: Trengganu 07
Diagram 6.1 shows a circuit to investigate
the working principle of a transistor.
The rheostat R is adjusted to get a set of
data of the microammeter reading , I1 and
the miliammeter reading, I2.
Diagram 4.1
(a) Name the type of transistor used.
.............................................................
[1 mark]
(b) The transistor is switched on when the
base voltage V2 ≥ 2 V.
(i) Write an equation to show the
relationship between IB, IC and IE.
.............................................................
[1 mark]
(ii) Calculate the minimum value of R2
when the transistor is switched on.
[2 marks]
(c) The resistor R2 is then replaced with a
light dependent resistor which has a high
resistance when it is dark.
(i) Explain whether the bulb will light up
during the day.
.............................................................
.............................................................
[2 marks]
(ii) Besides being used as a switch, state
one other use of a transistor.
Diagram 6.1
Table 6 shows the reading of I1 and I2.
I1 /μA
I2 /mA
0.0
0.0
0.5
0.2
1.0
0.4
1.5
0.6
2.0
0.8
2.5
1.0
Table 6
(a)
Name the current
(i)
I1 : ..........................................
[1 mark ]
(ii)
I2 : ..........................................
[1 mark]
(b) Using Table 6, state two observations
about the value of I1 and I2
..........................................................
..........................................................
[ 2 marks ]
(c)
Based on your answer in (b) state the
function a transistor.
........................................................
[ 1 mark ]
(d) The battery P is removed and replaced
by two resistors.
(i) Complete the circuit in Diagram
6.2 to ensure the transistor
workable without
battery P.
(a)(ii) Transistor has three terminals
connected to the emitter, base and
collector. Label the emitter, base and
collector in Diagram 7.1
[1 mark]
(b)
Diagram 7.2 shows a transistor circuit.
When the sliding contact X is at the 0 V end
of the potentiometer,
(i)
is there any current flow through
the base and emitter circuit?
(ii)
..................................................
[1 mark]
[ 2 marks ]
State the function of the two
resistors.
(ii)
..................................................
[ 1 mark ]
3. Question 7: Johor 08
Diagram 7.1 shows a semiconductor
transistor.
is there any current flow through
the base and emitter circuit?
[1 mark]
(iii)
If the sliding contact X were raised
from 0 V end to the 3 V end of the
potentiometer, what happened to
the bulb? Explain your answer
……………………………………
……………………………………
[2 marks]
(a)(i) Name the type of the transistor.
……………………………………….
[1 mark]
(c)
Diagram 7.3 shows a transistor is used
to light up during the day.
(a) Name the type of transistor shown in
Diagram 7.1.
............................................................
[1 mark]
(b) Based on Diagram 7.1:
(i) What is the potential difference
across point X and point Z?
(i)
Suggest a modification to light up the
lamp at night.
……………………………………….
[1 mark]
A student replaced lamp L with a lamp
labeled 240 V 24 W in Diagram 7.3.
(ii) The bulb is not light up.
Why the lamp is not light up?
……………………………………….
……………………………………….
[2 marks]
(iii)
An electrical component is connected
to the output transistor so that the
lamp is light up. Name the electrical
component and state the functions.
……………………………………….
……………………………………….
[2 marks]
4. Question 7: SBP 07
Diagram 7.1 shows a transistor circuit with
a bulb L.
.............................................................
[1 mark]
(ii) What is the total resistance between
point X and point Z?
..................................................................
[1 mark]
(iii) Using the answers from (b)(i) and
b(ii), calculate the potential
difference
[2 marks]
(c) State what will happen to the lamp,L, if
the base-emitter potential difference,
VBE is 2 volts? Explain your answer.
..........................................................
..........................................................
..........................................................
[2 marks]
(d) Without adding any new component to
Diagram 7.1, what modification is
needed so that the opposite situation
than the one in 7(c) occur at lamp L.
..........................................................
[1 mark]
(e) An automatic fire alarm is needed to
emit sound in case of fire. Suggest two
modifications that have to be made to
the circuit in Diagram 7.1 by replacing
the components with suitable electronic
components.
..........................................................
Diagram 7.1
..........................................................
..........................................................
[2 marks]
5. Question 8: Negeri 9 08
Diagram 8 shows a transistor circuit. The
circuit is used to automatically switch on the
bulb at night.
(a)(i) Name component Q.
(e) What happens to the bulb when it is
connected directly to the transistor
circuit without using the relay
switch. Explain why.
.....................................................
.....................................................
[2 marks]
6. Question 8: Melaka 08
Diagram 8.1 shows four electrical circuits
with identical electrical components.
The electrical circuits consist of a transistor
, a bulb, a light dependent resistor, LDR,
two resistors, R1 and R2 and battery as a
power supply.
........................................................
[1 mark]
(a)(ii) State two functions of
component Q?
........................................................
[2 marks]
(d) What is the function of resistor R?
.........................................................
[1 mark]
(c)(i) What happens to potential
difference VP at night? Explain.
........................................................
........................................................
[2 marks]
(c)(ii) Explain why the bulb is lighted
up at night?
........................................................
........................................................
[2 marks]
(d)
Bulb M is labelled 240 V, 60 W starts
to light up when VP is 2.0 V and the
resistance of resistor P is 10 kΩ.
Determine the maximum resistance of
resistor S.
[2 marks]
(a) What is meant by power?
..........................................................
[1 mark]
(b) Based on Diagram 8.1, state the suitable
characteristic of the arrangement
position of the
electrical
components of the circuit to use as an
automatic switch.
(i) Resistor, R2
..........................................................
Reason
.........................................................
[2 marks]
(ii) Resistor R1 and light dependent
resistor, LDR
...........................................................
[ 1 mark]
Reason
...........................................................
[2 marks]
(iii) Collector terminal of the transistor to
the battery
...........................................................
Reason
...........................................................
[2 marks]
(c) Based on the answers in 8(b), state one
suitable circuit in Diagram 8 to be use
as an automatic switch.
.
............................................................
[ 1 mark]
(d) The circuit in 8(c) is used as an
automatic switch. State the application
of the circuit.
...........................................................
[ 1 mark]
(e) Diagram 8.2 show a circuit transistor
used as an amplifier. The transistor is
on when the
voltage across
Y and Z is 1 V.
When the potential difference accross
Yand Z is 1 V;
(i) What is the potential difference
between X and Y?
(ii) Calculate the maximum resistance
of the rheostat for the transistor to
switch on?
[2 marks]
1. Question 4: Kedah 07
Diagram 4.1 shows the use of a transistor in
a circuit.
........................................................
[1 mark]
2. Question 6: Trengganu 07
Diagram 6.1 shows a circuit to investigate
the working principle of a transistor.
The rheostat R is adjusted to get a set of
data of the microammeter reading , I1 and
the miliammeter reading, I2.
Diagram 4.1
(a) Name the type of transistor used.
.............................................................
[1 mark]
(b) The transistor is switched on when the
base voltage V2 ≥ 2 V.
(i) Write an equation to show the
relationship between IB, IC and IE.
.............................................................
[1 mark]
(ii) Calculate the minimum value of R2
when the transistor is switched on.
[2 marks]
(c) The resistor R2 is then replaced with a
light dependent resistor which has a high
resistance when it is dark.
(i) Explain whether the bulb will light up
during the day.
.............................................................
.............................................................
[2 marks]
(ii) Besides being used as a switch, state
one other use of a transistor.
Diagram 6.1
Table 6 shows the reading of I1 and I2.
I1 /μA
I2 /mA
0.0
0.0
0.5
0.2
1.0
0.4
1.5
0.6
2.0
0.8
2.5
1.0
Table 6
(a)
Name the current
(i)
I1 : ..........................................
[1 mark ]
(ii)
I2 : ..........................................
[1 mark]
(b) Using Table 6, state two observations
about the value of I1 and I2
..........................................................
..........................................................
[ 2 marks ]
(c)
Based on your answer in (b) state the
function a transistor.
........................................................
[ 1 mark ]
(d) The battery P is removed and replaced
by two resistors.
(i) Complete the circuit in Diagram
6.2 to ensure the transistor
workable without
battery P.
(a)(ii) Transistor has three terminals
connected to the emitter, base and
collector. Label the emitter, base and
collector in Diagram 7.1
[1 mark]
(b)
Diagram 7.2 shows a transistor circuit.
When the sliding contact X is at the 0 V end
of the potentiometer,
(i)
is there any current flow through
the base and emitter circuit?
(ii)
..................................................
[1 mark]
[ 2 marks ]
State the function of the two
resistors.
(ii)
..................................................
[ 1 mark ]
3. Question 7: Johor 08
Diagram 7.1 shows a semiconductor
transistor.
is there any current flow through
the base and emitter circuit?
[1 mark]
(iii)
If the sliding contact X were raised
from 0 V end to the 3 V end of the
potentiometer, what happened to
the bulb? Explain your answer
……………………………………
……………………………………
[2 marks]
(a)(i) Name the type of the transistor.
……………………………………….
[1 mark]
(c)
Diagram 7.3 shows a transistor is used
to light up during the day.
(a) Name the type of transistor shown in
Diagram 7.1.
............................................................
[1 mark]
(b) Based on Diagram 7.1:
(i) What is the potential difference
across point X and point Z?
(i)
Suggest a modification to light up the
lamp at night.
……………………………………….
[1 mark]
A student replaced lamp L with a lamp
labeled 240 V 24 W in Diagram 7.3.
(ii) The bulb is not light up.
Why the lamp is not light up?
……………………………………….
……………………………………….
[2 marks]
(iii)
An electrical component is connected
to the output transistor so that the
lamp is light up. Name the electrical
component and state the functions.
……………………………………….
……………………………………….
[2 marks]
4. Question 7: SBP 07
Diagram 7.1 shows a transistor circuit with
a bulb L.
.............................................................
[1 mark]
(ii) What is the total resistance between
point X and point Z?
..................................................................
[1 mark]
(iii) Using the answers from (b)(i) and
b(ii), calculate the potential
difference
[2 marks]
(c) State what will happen to the lamp,L, if
the base-emitter potential difference,
VBE is 2 volts? Explain your answer.
..........................................................
..........................................................
..........................................................
[2 marks]
(d) Without adding any new component to
Diagram 7.1, what modification is
needed so that the opposite situation
than the one in 7(c) occur at lamp L.
..........................................................
[1 mark]
(e) An automatic fire alarm is needed to
emit sound in case of fire. Suggest two
modifications that have to be made to
the circuit in Diagram 7.1 by replacing
the components with suitable electronic
components.
..........................................................
Diagram 7.1
..........................................................
..........................................................
[2 marks]
5. Question 8: Negeri 9 08
Diagram 8 shows a transistor circuit. The
circuit is used to automatically switch on the
bulb at night.
(a)(i) Name component Q.
(e) What happens to the bulb when it is
connected directly to the transistor
circuit without using the relay
switch. Explain why.
.....................................................
.....................................................
[2 marks]
6. Question 8: Melaka 08
Diagram 8.1 shows four electrical circuits
with identical electrical components.
The electrical circuits consist of a transistor
, a bulb, a light dependent resistor, LDR,
two resistors, R1 and R2 and battery as a
power supply.
........................................................
[1 mark]
(a)(ii) State two functions of
component Q?
........................................................
[2 marks]
(d) What is the function of resistor R?
.........................................................
[1 mark]
(c)(i) What happens to potential
difference VP at night? Explain.
........................................................
........................................................
[2 marks]
(c)(ii) Explain why the bulb is lighted
up at night?
........................................................
........................................................
[2 marks]
(d)
Bulb M is labelled 240 V, 60 W starts
to light up when VP is 2.0 V and the
resistance of resistor P is 10 kΩ.
Determine the maximum resistance of
resistor S.
[2 marks]
(a) What is meant by power?
..........................................................
[1 mark]
(b) Based on Diagram 8.1, state the suitable
characteristic of the arrangement
position of the
electrical
components of the circuit to use as an
automatic switch.
(i) Resistor, R2
..........................................................
Reason
.........................................................
[2 marks]
(ii) Resistor R1 and light dependent
resistor, LDR
...........................................................
[ 1 mark]
Reason
...........................................................
[2 marks]
(iii) Collector terminal of the transistor to
the battery
...........................................................
Reason
...........................................................
[2 marks]
(c) Based on the answers in 8(b), state one
suitable circuit in Diagram 8 to be use
as an automatic switch.
.
............................................................
[ 1 mark]
(d) The circuit in 8(c) is used as an
automatic switch. State the application
of the circuit.
...........................................................
[ 1 mark]
(e) Diagram 8.2 show a circuit transistor
used as an amplifier. The transistor is
on when the
voltage across
Y and Z is 1 V.
When the potential difference accross
Yand Z is 1 V;
(i) What is the potential difference
between X and Y?
(ii) Calculate the maximum resistance
of the rheostat for the transistor to
switch on?
[2 marks]
