Potential Difference

Question 1

What do we need for charge to flow ?

Answer 1

We need to do work on it

Question 2

What is potential difference ?

Answer 2

The work done per unit charge to transfer electrical energy into other forms of energy.

Question 3

Equation for potential difference? What do the symbols represent ?

Answer 3

V = W/Q  
V = pd  
W = work done  
Q = charge

Question 4

What is potential difference measured with and how does this component need to be connected ?

Answer 4

With a voltmeter in parallel

Question 5

What is special about a voltmeter?

Answer 5

It has a large resistance value to limit current effecting the value of pd.

Question 6

What happens to pd in series.

Answer 6

It is different for components as electrical energy is transferred to other energy stores.

Question 7

What happens to pd in parallel. What law does this apply to?

Answer 7

It stays the same , this is because the total pd in a loop must equal to zero. (So pd from battery + ps at resistor in loop =0)

Kirchoff’s 2nd Law.

Question 8

What is Kirchoff’s 2nd Law ?

Answer 8

In a closed loop pd and emf must have a sum of 0 to avoid losing energy.