Potential difference

Question 1

What is potential difference?

Answer 1

• Potential difference is the difference in energy between two points in a cirucit.
  points refers to coulomb of charge

Question 2

What is meant by something having a potential difference of 6V?

Answer 2

• This means 6J of electrical energy is transferred for each coulomb of charge that passes through.

Question 3

What energy transfers occur in an electrical circuit with a lamp?

Answer 3

• Battery has chemical energy
• Electrons have electrical energy
• Lamp has thermal energy

Question 4

What 3 types of voltmeters are there?

Answer 4

• Analog
• Digital
• Multimeter

Question 5

How should a voltmeter be connected to measure potential difference?

Answer 5

• In parallel with the component.

Question 6

How does potential difference change in a series circuit?

Answer 6

• Spread amongst components
• Not always equally!!

Question 7

How does potential difference change in a parallel circuit?

Answer 7

• Each branch has same potential difference.
• The components on branch split potential difference.

Question 7

What is meant by a battery having a potential difference of 9V?

Answer 7

• This means that 9J of electrical energy is transferred to the component for each coulomb of charge that passes through.

Question 8

What is the equation for calculating potential difference?

Answer 8

Potential difference = Energy transferred/ Charge flow

Question 9

What is another way of writing the equation for potential difference?

Answer 9

Energy transferred/ Current x Time
*From V=EQ

Question 10

How does a coulomb of charge having more energy affect the current?

Answer 10

• The electrons (coulomb) are moving faster, so current increases.

Question 11

How does the potential difference drive current?

Answer 11

• Each coulomb of charge has energy that drives the charge to move.
  The potential difference is the force that moves charge

Question 12

If you increase voltage of circuit, what happens to resistance?

Answer 12

• Resistance increases (if current is constant)

Question 13

What is a “potential divider circuit?”

Answer 13

• When P.D is split between 2 or more components.

Question 14

Q.)

What happens to P.D if I increase ressistance of a bulb in a parallel circuit?

Answer 14

• Nothing
• Doesn’t change in parallel circuits

Question 15

How do you work out the potential difference of a battery, given that of the cells?

Answer 15

• Just multiply voltage of cells to the number of cells you have.
• If cells are facing each other, the P.D cancels out.

Question 16

3 cells are connected together to form a battery.
Each cell has P.D of 5V
Two are in the correct direction
One is in incorrect direction
What is total voltage of battery?

Answer 16

5V
5V - 5V = cancel each other out.