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WorksheetsAS - electricity
Total questions: 26
Worksheet time: 47mins
This is a graph for a ..............................
LDR
Thermistor
Diode
Resistor
Filament lamp
This is a graph for a ...............................................
LDR
Thermistor
Diode
Resistor
Filament lamp
As the temperature increases, the resistance
increases
decreases
stays the same
can not say
What is the correct symbol for a LDR (light dependent resistor)?
What is the correct symbol for a thermistor?
In the equation I=nAve, which optionS correctly describe the meaning of n?
the charge carrier density
the number of charge carriers per unit volume
the number of charge carriers per m3
the number of charge carriers in the wires
the total charge carriers available in the battery
If the current in a specific copper wire increases this can be due to _____________________.
An increase in the charge carrier density
An increase in the electron drift speed
An decrease in its cross sectional area
An increase in the charge of electrons
The graph shows the change in current with potential difference for
an LED
a filament lamp
a diode
a thermistor
To calculate the resistance of the component at a particular potential difference you
read the current at that point on the graph and calculate p.d divided by current
draw a tangent to the line at that point and calculate the gradient
draw a tangent to the line at that point and calculate 1/gradient
read the current at that point on the graph and calculate current/p.d
The resistance of the component
is always constant as the p.d. increases
starts high and then decreases as the p.d. increases
starts constant for low values of p.d. and then increases as the p.d. increases
starts constant for low values of p.d. and then decreases as the p.d. increases
What is Resistance?
how difficult it is for electrons to move through a circuit
How hard the energy is pushed
The amount of charges that pass by a given point per second
None of the above
What relationship is shown by this graph (choose two true statements)
A family relationship
A directly proportional relationship
A non-linear relationship
An inverse relationship
What happens to the resistance of a filament lamp as the potential difference increases? Why?
It is constant. The resistance of a filament lamp always remains the same.
It decreases. As the potential difference increases, more electrons are pushed through the wire in the lamp in a smaller time and so the resistance decreases.
It increases. As the potential difference increases, the current also increases which heats the filament increasing the number of collisions between electrons and lattice atoms.
May be I should revise this topic before the exam.
Which one of these components is designed to break the circuit, if the current becomes too high?
ammeter
variable resistor
fuse
lamp
Why does the resistance increase as the potential difference increases for a lamp?
The current remains constant, so from V = IR, if V increases, R increases.
The filament heats up, the ions vibrate more and collide together with each other.
The filament heats up, the ions vibrate more and so there are more collisions between ions and electrons.
The filament heats up, the ions remain stationary and allow the electrons to pass through.
If a current of 1.2 A passes through a lamp, and it has a potential difference of 18 V across it. What is the resistance of the lamp?
15 Ohms
15 Amps
0.067 Ohms
21.6 Amps
Which of the following does this graph apply to?
A diode
A fixed resistor
A filament lamp
A thermistor
Which of the following does this graph apply to?
diode
filament lamp
fixed resistor
a thermistor
Which of the following does this graph apply to?
diode
filament lamp
fixed resistor
a thermistor
Which of the following has this circuit symbol?
diode
fixed resistor
filament lamp
A thermistor
Which component is this?
Variable resistor
Fuse
Thermistor
Diode
As current passes thorough a thermistor, what happens to its resistance and WHY?
a) What is Emf?
b) What is potential difference?
What is resistance?
As current passes through a filament lamp, what happens to its resistance and WHY?
State Ohm's Law.
