Size of current

Question 1

How is current affected by voltage and resistance in a circuit?

Answer 1

The larger the voltage of the battery in a circuit the bigger the current.
The larger the resistance of components in a circuit, the smaller the current

Question 2

What is power a measure of the rate of?

Answer 2

Power is a measure of the rate at which electrical power supplies transfer energy to an appliance

Question 3

What is the equation for power?

Answer 3

power (watts, W) = voltage (volts, V) * current (amperes, A)

Question 4

Why do resistors get hot?

How does this relate to lamps?

Answer 4

Resistors get hot when there is a current flowing through them, this heating effect is caused by collisions between the moving charges in the current and the stationary ions in the resistors.
The same occurs in a lamp, except the heat created is used and is hot enough to make the filament glow

Question 5

How does the resistance of an LDR and a thermistor vary?

Answer 5

In a LDR (light dependent resistor) as the amount of light falling on it increases the resistance decreases.
In a thermistor as the temperature of the resistor increases the resistance decreases.

Question 6

How does having two resistors in series affect resistance?

Answer 6

Having two or more resistors in series means that battery has to move charges through both of them and so the resistance is higher.

Question 7

How does having two resistors in parallel affect resistance?

Answer 7

Having two or more resistors in parallel means that the charges have more paths to move along than either on its own and so resistance is less

Question 8

What is the equation for resistance?

Answer 8

resistance (ohms,(omega)) =
voltage (volts, V) /
current (amperes, A)

Question 9

If resistance is constant how is current affected by a change in voltage?

Answer 9

When resistance is constant, if voltage increases, current increases proportionally and if voltage decreases, current does so to proportionally