Electricity Flashcards
State an equation that defines current
Current = Charge / Time, I = Q/t
Is the long end of the circuit symbol for a cell/battery the positive or the negative terminal?
Positive
Is the short end of the circuit symbol for a cell/battery the positive or the negative terminal?
Negative
State an equation that defines resistance?
Resistance = Voltage / Current, R= V/I
What is the unit of charge?
Coulomb (C)
What is the unit of current?
Amp (A)
What is the unit of voltage?
Volt (V)
What is the unit of power?
Watt (W)
What is the unit of resistance?
Ohm (Omega)
How does the resistance of a lamp change as temperature changes?
Increase in temperature, increase in resistance.
How does the resistance of a thermistor change as temperature changes?
Increase in temperature, decrease in resistance.
Why do currents produce heat?
Electrons collide with the metal atoms, transferring kinetic energy and making them vibrate more.
Why do metals increase in resistance when you increase the temperature?
Increase in temperature means larger, faster vibrations of the metal atoms which block more electrons trying to pass through, which increases resistance.
What is voltage?
The energy transferred per unit charge
