Electricity Flashcards
Describe what would happen to a positive charge if it was placed in the field shown.
A positive charge would accelerate towards the negative plate.
In the diagram shown, what type of charge does the particle have?
Explain your answer.
The particle has a negative charge.
The particle is negative because it is attracted to the positive plate.
What is the name of this component?
Motor
What is the name of this component?
Battery
How could the air-conditioning circuit (shown) be changed so that it switches on at a different temperature?
To switch the circuit on at a different temperature, the variable resistor could be adjusted.
What is the name of this component?
Variable resistor
What does the prefix G stand for?
G stands for giga
giga = x 109
What unit is resistance measured in?
Resistance is measured in ohms.
What unit is time measured in?
Time is measured in seconds (s).
What unit is current measured in?
Current is measured in amperes (A).
What is the name of this component?
Fuse
What is the name of this component?
Lamp
What is the energy change in a washing machine?
In a washing machine, the energy change is
electrical energy to heat and kinetic energy.
The voltage of a supply is a measure of the ………………. given to the charges in a circuit.
The voltage of a supply is a measure of the ENERGY given to the charges in a circuit.
What does the prefix µ stand for?
µ stands for micro
micro = x 10-6
What unit is voltage measured in?
Voltage is measured in volts (V).
Round off this number to 3 significant figures.
3.14159
3.14159 rounded off to 3 significant figures is
3.14
What is the name of this component?
Loudspeaker
Round off this number to 3 significant figures.
6.22789
6.22789 rounded off to 3 significant figures is
6.23
Round off this number to 3 significant figures.
1,526.33
1,526.33 rounded off to 3 significant figures is
1,530
(the ‘2’ has been rounded up to 3)
What does the prefix n stand for?
n stands for nano
nano = x 10-9
Round off this number to 3 significant figures.
0.0025668
0.0025668 rounded off to 3 significant figures is
0.00257
A hairdryer has an operating current of 6.5 amperes.
What value of fuse should be used in the plug of the hairdryer?
The fuse rating has to be higher than the operating current.
If the current is 6.5A, a 13A fuse should be used.
What is the name of this component?
L.E.D. (light-emitting diode)
How could the air-conditioning circuit (shown) be changed so that it performs the opposite job?
The circuit can be changed to perform the opposite job by swapping the thermistor with the variable resistor.
Which quantity is represented by the symbol t?
t = time
Which quantity is represented by the symbol V, in the equation shown ?
voltage
(or potential difference)
What unit is power measured in?
Power is measured in watts (W).
What does d.c. stand for and what does it mean?
d.c. stands for direct current, which means the electrons flow in one direction only (negative to positive).
What is the purpose of a transistor?
A transistor acts as an electronic switch.
(it switches on above a certain voltage)
Describe how to use an ammeter to measure the current in a component.
An ammeter must be connected in series with a component.
How many pencils are there?
Will the L.E.D. in this circuit switch on?
Explain your answer.
No - the L.E.D. will not switch on.
The positive terminal of the L.E.D. is not connected to the positive terminal of the battery.
What is the name of this component?
npn transistor
How could the resistance of a component be found from this graph?
The resistance could be found by
(a) calculating the gradient of the graph
(b) choosing a point on the graph and calculating voltage / current
What unit is energy measured in?
Energy is measured in joules (J).
Which quantity is represented by the symbol R?
R = resistance
Name as many different types of energy as possible.
Kinetic, potential, electrical, chemical, light, heat, sound, nuclear
What is the definition of current?
Current is how much electrical charge flows (past a point) in one second.
Which quantity is represented by the symbol P, in the equation shown?
P = power
What unit is charge measured in?
Charge is measured in coulombs (C).
Will the L.E.D. in this circuit switch on?
Explain your answer.
Yes - the L.E.D. will switch on.
The positive terminal of the L.E.D. is connected to the positive terminal of the battery.
Describe what would happen to a negative charge if it was placed in the field shown.
A negative charge would accelerate towards the positive plate.
What is the name of this component?
L.D.R. (light-dependent resistor)
What does the prefix k stand for?
k stands for kilo
kilo = x 103
What is the name of this component?
Cell
Why does an L.E.D. always have a resistor connected in series with it?
An L.E.D. always has a resistor connected in series with it to protect the L.E.D.
The resistor will limit the current in the L.E.D.
What is the definition of the term power?
Power is defined as the amount of energy used per second.
How many types of electric charge are there, and what are their names?
There are two types of electric charge - positive and negative
What effect does an electric field have on a charge?
An electric field causes a charge to move.
What does the prefix M stand for?
M stands for mega
mega = x 106
What is the value of mains voltage (in the UK)?
Mains voltage is 230V.
What is the name of this component?
Resistor
What is the name of this component?
MOSFET (transistor)
Which quantity is represented by the symbol Q?
Q = charge
Which quantity is represented by the symbol I?
I = current
What is the name of this component?
Capacitor
What does the prefix m stand for?
m stands for milli
milli = x 10-3
What is the name of this component?
Diode
What does a.c. stand for, and what does it mean?
a.c. stands for alternating current, which means the electrons change direction every fraction of a second.
Describe how to use a voltmeter to measure the voltage across a component.
A voltmeter must be connected in parallel with a component.
