Separate Physics - P2 Electricity Flashcards
What is the circuit symbol for an open switch?
What is the circuit symbol for a closed switch?
What is the circuit symbol for a cell?
What is the circuit symbol for a battery?
What is the circuit symbol for a diode?
What is the circuit symbol for a resistor?
What is the circuit symbol for a variable resistor?
What is the circuit symbol for an LED?
What is the circuit symbol for a lamp?
What is the circuit symbol for a fuse?
What is the circuit symbol for a voltmeter?
What is the circuit symbol for an ammeter?
What is the circuit symbol for a thermistor?
What is the circuit symbol for an LDR?
What is current?
The rate of flow of charge
What equation links charge flow, current and time?
Charge flow = current x time
Q = I t
Describe the IV graph for a resistor at constant temperature.
- Current is directly proportional to potential difference.
- Resistance is constant.
What type of circuit is shown in the image?
Series circuit
Explain the shape of the IV graph for a diode.
- Current only flows in one direction through a diode.
- There is high resistance in the opposite direction meaning current doesn’t flow.
What equation links potential difference, current and resistance?
Potential difference = current x resistance
V = I R
What type of circuit is shown in the image?
Parallel circuit
Draw an I-V graph for a filament lamp.
For a given potential difference, what happens to the current when the resistance increases?
The current decreases.
Explain the shape of the IV graph for a filament lamp.
As the current increases the temperature of the filament lamp increases (so the resistance increases) meaning less current can flow per unit potential difference.
Draw an I-V graph for an ohmic resistor (e.g. a resistor at a constant temperature).
Draw an I-V graph for a diode.
What happens to the resistance of a thermistor as temperature increases?
Resistance decreases
What happens to the resistance of an LDR as light increases?
Resistance decreases
What’s the difference between direct current and alternating current?
- Direct current flows in only one direction.
- Alternating current constantly changes direction.
What is the rule for current in a series circuit?
Current is the same everywhere in the circuit
Name the electrical component used in thermostats.
Thermistor
Where are LDRs commonly found?
LDRs are used as automatic night lights / burglar detectors (in bright light the resistance is low)