Download ELECTRONICS HOMEWORK 1 1. Make a table with two columns

ELECTRONICS HOMEWORK 1
1. Make a table with two columns headed Analogue and Digital. Place the following
electronic devices into one of the two columns: (4)
7 segment display, motor, solenoid, bulb, LED, loudspeaker,
2. What is the difference between an analogue watch and a digital watch? (2)
3. CD players, hi-fi units and televisions all have amplifiers in them. The amplifier is a
process device used to add energy to the input signal before it is output as sound. Is an
amplifier an analogue or a digital process? (1)
4.Copy and complete the following table:
OUTPUT
DEVI
(3)
ELECTRONICS HOMEWORK 2
OUTPUT DEVICE ENERGY CHANGE SYMBOL
(
1. (a) Name the component marked X in the circuit. (1)
(b) What would happen in the circuit if component X was connected the opposite way
around? (1)
(c) Why must there always be a resistor in series with this component? (1)
2. An LED is attached to a 6 V supply: Maximum forward voltage: 2.7 V. Maximum forward
current: 110 mA
(a) Draw the symbol for an LED (1)
(b) Draw a circuit diagram that will allow this LED to light safely. (3)
(c) Calculate the value of the resistor needed. (3)
ELECTRONICS HOMEWORK 3
1. (a) Why is a seven-segment display so-called? (1)
(b) Draw the numbers (i) 3; (ii) 9 as they'd appear on a seven-segment display. (2)
(c) What range of numbers can be displayed on a single seven-segment display? (1)
2. A voltage divider circuit is shown below
200Ω
V2
600Ω
V1
12V
Calculate the voltage across V1 and V2.
3.
(3)
A voltage divider circuit is shown below
12V
1200
Ω
V2
600Ω
V1
Calculate the voltage across V1 and V2.
(3)
ELECTRONICS HOMEWORK 4
1.
A voltage divider circuit is shown below
200Ω
V2
1600
Ω
V1
12V
Calculate the voltage across V1 and V2.
2.
(4)
The circuit below is part of a temperature control circuit.
Rt
V2
12V
RV
V1
The variable resistor is set to 100Ω .
The resistance of the thermistor at different temperatures is shown in the table below.
Temperature
Resistance of thermistor
(°C)
(Ω)
20
500
40
200
60
60
80
20
4. What is happening to the resistance of the thermistor as the temperature increases? (1)
5. Calculate the voltage across the variable resistor when the temperature is
(i) 20°C
(1 ½)
(ii) 80°C
(1 ½)
3. Consider the following circuit:
5kΩ
V2
1.5MΩ
V1
12V
Calculate the voltage across the 5kΩ resistor.
(2)
ELECTRONICS HOMEWORK 5
1.
Draw the symbol for a cell, lamp, motor and ammeter
(2)
2. A boy sets up the following circuit in his Physics lab.
12V
A
(a)
What type of resistor is
(b)
The resistance of
(½)
is 2kΩ when the room temperature is 23°C, calculate
the reading on the ammeter.
(2)
(c ) A boy opens a window in the room and it drops to 21°C, What
happens to the reading on the ammeter? justify your answer
3.
(2)
RV in the last question is replaced by an LDR
(a)
Draw the symbol for an LDR
(½)
(b)
A man and his wife decide to go on holiday, they want a lamp to go on in
their house when it gets dark to prevent their house being burgled.
They have 2 choices
They could buy a device that switches their lamp on every night at 7pm.
The second device has an LDR and a resistor in it.
Which device would be better, explain your answer
(3)
ELECTRONICS HOMEWORK 6
1 A switch and a resistor are placed in a circuit as shown, the voltage is measured
across the switch when it is open and closed.
1.5V
V
What is the reading on the voltmeter with the switch
(i) Open?
(ii) Closed?
2.
(2)
Look at the circuit below
6v
X
V
v
V
V
(a) Name component X V
(1)
V
(b) (i)What is the reading on the voltmeter when the switch is open
(1)
V
(ii)What is the reading on the voltmeter with the switch closed
(1)
V
V fills up with charge. The resistor R is now replaced
(c) Component X gradually
V does this affect the
by a larger resistor. How
v
(i)
time of charging
(1)
V
(ii)
maximum voltage
(1)
V across the capacitor.
V
(b) State 2 ways to speedVup the time of charging
(2)
d
(c ) Name one electronic system that uses this type of circuit
V
(1)
Homework 7
1. (a) Draw the circuit symbol for a transistor(1).
(b) Give one use for a transistor in an electronic circuit(1).
(
(
2. The circuit shown below is used as an alarm.
+5 V
T
Buzzer
R
(a) The thermistor is positioned in a car engine. At normal engine
temperatures, the transistor is OFF. What will happen if the
engine overheats?(1)
(b) Explain how the circuit works.(3)
©If the fixed resistor has a value of 1kΩ and the thermistor a value
of 20kΩ will the buzzer sound (3)
(d) How would a variable resistor instead of the fixed resistor
improve this circuit(1)
(