V=IR Characteristics and P&S Circuits

Question 1

How do you find the total resistance of a series circuit?

Answer 1

Add together the resistances of each component in the circuit.

Question 2

What does a current/voltage graph look like for a filament lamp?

Answer 2

Like a lowercase F across the x and Y axis

Question 3

How does potential difference work in a parallel circuit?

Answer 3

All the components in a parallel circuit have the same potential difference.

Question 4

What is a fixed resistor?

Answer 4

A resistor that has a fixed resistance that cannot be changed.

We normally just refer to them as a ‘resistor’.

Question 5

How does a thermistor work?

Answer 5

As temperature increases, the resistance of a thermistor decreases

INVERSE

Question 6

What is a variable resistor?

Answer 6

A resistor whose resistance can easily be changed by moving a slider.

Question 7

How does a LDR/Light Dependent Resistor Work?

Answer 7

As light intensity increases, the resistance of an LDR decreases.

Question 9

What happens to resistance in a parallel circuit?

Answer 9

The more loops you have in a parallel circuit, the lower the total resistance will be.

This is true regardless of the resistance of each component.

Question 10

What happens to current in a series circuit?

Answer 10

Current is the same for every component in a series circuit.

Question 11

For wires and resistors, how does temperature affect resistance?

Answer 11

Increasing the temperature will increase the resistance.

Question 13

What is the formula that links current, resistance, and voltage?

Answer 13

voltage (V) = current (I) x resistance (R)

V = IR

Question 14

In a series circuit, do the components with the largest resistance get the largest or smallest share of the potential difference?

Answer 14

In a series circuit, components with the largest resistance get the largest share of the potential difference

Question 15

What happens to the potential difference in a series circuit?

Answer 15

It is shared across all the components.

Question 16

What is a parallel circuit?

Answer 16

A parallel circuit is a circuit in which each component has its own loop

Question 17

What happens to current in a parallel circuit?

Answer 17

The total current is shared between all of the parallel loops. So to find the total current, you must add together the currents of each loop.

Question 18

What does a diode do?

Answer 18

Diodes only allow current to flow one way around a circuit.

Question 19

What is the main advantage of a parallel circuit?

Answer 19

If one component breaks, the circuit as a whole will continue to work.

Question 20

What is the main advantage of a series circuit?

Answer 20

Series circuits are simple to set up.

Question 21

What is a thermistor?

Answer 21

A resistor whose resistance decreases as temperature increases.

Question 22

What does a voltmeter do?

Answer 22

Measures the potential difference (voltage) across a component.

Question 23

Where should voltmeters be placed?

Answer 23

In parallel across the component you’re interested in.

Question 24

What is a series circuit?

Answer 24

A series circuit is a circuit in which all the components are in the same loop.

Question 25

What is a light dependent resistor (LDR) used for?

Answer 25

To measure light intensity.

For example, in automatic night lights.

Question 26

Where should an ammeter be placed?

Answer 26

Series

Question 27

What is a light dependent resistor (LDR)?

Answer 27

A resistor whose resistance decreases as light intensity increases.

Question 28

What is a thermistor used for?

Answer 28

To measure the temperature.

For example, in car engines or thermostats.

Question 29

What does a light emitting diode (LED) do?

Answer 29

And LED will emit light when current flows through it, and only allow current to flow in one direction.

Question 30

What is the main disadvantage of a series circuit?

Answer 30

If any single component breaks, the whole circuit will stop working.

Question 31

Why does increasing the temperature of a wire increase its resistance?

Answer 31

At higher temperatures, the particles in the wire vibrate faster, which impedes (slows) the flow of electrons, increasing the resistance.

Question 32

What is Ohm’s Law?

Answer 32

Ohm’s law describes the relationship between voltage, current, and resistance:

V = IR