• Work?is done when charge flows through a circuit
  • Work done is equal to the?energy transferred

   

• The amount of energy transferred by electrical work in a component (or appliance) depends upon:
  • The?current,?I
  • The?potential difference,?V
  • The amount of?time?the component is used for,?t

   

• When charge flows through a resistor, for example, the energy transferred is what makes the resistor?hot
• The energy transferred can be calculated using the equation:

E?=?P?×?t

• Where:
  • E?= energy transferred in joules (J)
  • P =?power in watts (W)
  • t?= time in seconds (s)

   

• Since?P = IV, this equation can also be written as:

E?=?I?×?V?×?t

• Where:
  • I?= current in amperes (A)
  • V?= potential difference in volts (V)

   

• When charge flows around a circuit for a given time, the energy supplied by the battery is equal to the energy transferred to all the components in the circuit

Step 1: Write down the known quantities

• • Time,?t?= 1 minute = 60 s
  • Current,?I?= 0.7 A
  • Potential difference,?V?= 4 V

   

Step 2: Write down the relevant equation

E?=?I × V × t

Step 3: Substitute in the values

E?= 0.7 × 4 × 60 =?168 J