Physics Homework [Electricity 3] Flashcards
09.06.25 (20 cards)
When measuring the resistance of a piece of wire, explain why the potential difference should be kept small.
So there is a small current and the wire does not heat up as much.
State the standard units for resistance.
Ohms (Omega)
In the circuit diagram, compare the current at X with the current at Y
No difference.
Give a use of LDRs
Light sensors that can switch the light on when it gets dark.
Explain which of these diagrams shows a voltmeter connected correctly to measure the potential difference across the bulb.
B because the voltmeter is connected in parallel to the bulb.
Describe the relationship between potential difference and current for an ohmic conductor (resistor)
Current is directly proportional to potential difference.
Describe the current throughout a closed loop within a circuit.
It has the same value everywhere in the circuit.
The diagram shows an I-V curve. Name the component that would produce this curve.
Diode
In a thermistor, describe how the resistance varies with temperature.
As the temperature increases, the thermistor’s resistance decreases.
State the standard units for charge.
Coulombs (C)
Name the only component whose resistance stays constant with increasing current.
Ohmic conductor (resistor)
State the standard units for potential difference.
Volts (V)
The diagram shows an I-V curve. Name the component that would produce this curve (S shape)
Filament lamp
Define the size of an electrical current in terms of electrical charge.
The rate of flow of electrical charge.
Give a use of thermistors.
Electronic temperature sensors such as thermostats.
State the standard units for current.
Amperes or amps (A)
What does LED stand for?
Light-emitting diode.
State the function of a diode.
To allow current to flow in one direction only.
Explain why the resistance of a filament lamp increases with current.
The increased current increases the temperature.
Explain which of these diagrams shows an ammeter connected correctly to measure the current through the bulb.
A, it is in series with the bulb.
