Higher
Electricity
QUESTION 1
What is the definition of
electrical current?
QUESTION 2
What is the definition of
potential difference?
QUESTION 3
What is the definition of
‘electrical power’ ?
QUESTION 4
Calculate the resistance
between X and Y.
QUESTION 5
When the switch closes, what
happens to the readings on the
ammeter and the voltmeter?
QUESTION 6
Calculate the resistance between
X and Y.
QUESTION 7
Calculate the resistance between
A and B.
QUESTION 8
Calculate or find the readings on the ammeter
and the voltmeter when:
a) the switch S is open.
b) the switch S is closed.
QUESTION 9
What is the purpose of Wheatstone
Bridge Circuits?
QUESTION 10
State two things about a
Wheatstone Bridge Circuit which
will indicate that it is balanced.
QUESTION 11
When Rv is increased from 10kΩ,
what will the graph look like of
V against ΔR?
QUESTION 12
Calculate the reading on the voltmeter
in the unbalanced Wheatstone Bridge
circuit shown below.
QUESTION 13
State the definition of EMF.
QUESTION 14
What is meant by a ‘terminal
potential difference’ of 5V?
QUESTION 15
State the three variations of the
EMF equation.
QUESTION 16
Which two pieces of information can be
taken from the graph below when it cuts
the y-axis and the x-axis?
QUESTION 17
Find the internal resistance of the
battery from the graph below.
QUESTION 18
Calculate the reading on the ammeter,
when the switch is open and when the
switch is closed.
QUESTION 19
What is meant by the term
‘short circuit current’?
QUESTION 20
Under what conditions do you have
maximum power transfer in a circuit
from a battery with an internal
resistance r?
QUESTION 21
The circuit below is used to find the emf
E and internal resistance r of a battery.
QUESTION 21 (Cont’d)
The following information in the table below is found
by closing different combinations of the switches S1,
S2 and S3.
a) Complete the table.
b) Draw a graph of V against I to find:
i) EMF of the battery
ii) Internal resistance of the battery.
c) Why does the terminal potential difference
of the battery increase as the current in the
circuit decreases?
QUESTION 22
A battery of emf E of 4.5V and an internal
resistance r of 1.2Ω is set up as shown below.
QUESTION 22 (Cont’d)
a) What is meant by an emf E of 4.5V?
b) Switch S1 is now closed. Calculate or find:
i) the reading on the ammeter.
ii) the reading on the voltmeter.
c) Describe what happens to the readings on the
ammeter and voltmeter at the instant when switch
S2 is closed.
QUESTION 23
State the mains voltage and mains
frequency of the supply in the UK.
QUESTION 24
State the names of the controls on an
oscilloscope used to measure
a) Peak Voltage and Frequency.
b) Describe how the ac wave pattern
explains how the current flows from the
supply in an ac circuit.
QUESTION 25
If the oscilloscope is set at 5V/div, then
calculate the peak voltage and the rms
voltage from the wave trace below.
QUESTION 26
If the oscilloscope is set at 10ms/div,
then calculate the frequency of the
wave trace below.
QUESTION 27
State two observations of the wave
trace below if the oscilloscope setting
is changed from 5ms/div to 20ms/div.
QUESTION 28
A peak current of 0.37A flows through
a lamp of resistance 885 Ω.
Calculate the power of the lamp.
QUESTION 29
Calculate the peak voltage and the peak
current from the circuit below.
QUESTION 30
A signal generator is connected to an oscilloscope
and is set to a peak voltage of 12V. The Y-gain
setting is omitted and the time-base setting is set at
1.0ms/div.
Calculate or find:
a) Y-gain of the oscilloscope.
b) Frequency of the signal in Hertz.
QUESTION 31
Find the following from the wave trace produced from an ac
source with the following settings on the oscilloscope.
Y-gain setting = 5V div-1
Time-base setting 10ms div-1.
a) Peak Voltage Vp
b) Root Mean Square Voltage Vrms
c) Frequency of the source.
QUESTION 32
What do capacitors store and what
type of circuits would you find them in?
QUESTION 33
State the unit for Capacitance and give
another unit which is equivalent to it.
QUESTION 34
State what is meant by a capacitor
having a capacitance of 3000µF.
QUESTION 35
A capacitor is marked 6V,120µF.
Calculate the maximum charge and the
maximum energy that it can store.
QUESTION 36
If the capacitance and resistance are both
increased in the diagram below, then
sketch the new waveform produced.
QUESTION 37
Calculate the energy stored in the
capacitor below, when the voltage
across it is 8V.
QUESTION 38
QUESTION 39
What will happen to the readings on
each ammeter when the frequency of
both supplies are increased?
QUESTION 40
In the circuit below the capacitor starts to charge up
when the switch S is closed.
a) Calculate the maximum charging current during
the charging process.
b) Calculate the charging current when the potential
difference across the capacitor is 6V.
c) Calculate the extra energy stored when the voltage
across the capacitor increases from 6V to 9V.
QUESTION 41
A 7.5V dc power supply is connected as shown in
the circuit below.
When the switch is closed the capacitor starts to
charge up.
Sketch the following graphs with axes and list the
quantities and units labelled for:
a) Charging Current (I) against time (t).
b) Voltage across the Capacitor (Vc) against time (t).
QUESTION 42
Name the process involved when
impurity atoms are added to form a
p-type or an n-type semiconductor
material.
QUESTION 43
Name the two types of bias that a
p-n material can be connected up in
with a battery.
QUESTION 44
State the charge present in p-type and
n-type semiconductor materials and
what type of charge carriers do they
both prefer?
QUESTION 45
Name component X, state the mode it is
operating in and describe how it will turn
the electric motor.
QUESTION 46
What difference is noticeable between
the conduction and valence bands in
semiconductors and insulators when
comparing them?
QUESTION 47
What happens to the band gap in a
semiconductor material when the
temperature increases?
QUESTION 48
a) State the names of the materials 1,2 and 3
in the diagram below.
b) Which of the bands is the high energy band?
c) Compare the abundance of electrons in the
high energy band for the three materials.
QUESTION 49
The graph below shows a range of wavelengths emitted
from an LED and the relative light output from it.
Calculate the minimum energy of a photon
emitted from this LED.
QUESTION 50
Explain using Band Theory how
LED’s emit photons of light.
The End