Electric Current

Numerical Problems

These numerical problems are based on the chapter Electricity class 10 science of NCERT books and CBSE syllabus.

Example 1: Find the amount of electric charge flowing through the circuit if an electric current of 5 A is drawn by an electric appliance for 5 minute.

Solution: Given, electric current (I) = 5 A

Time (t) = 5 minute `= 5 xx 60 = 300` s

Electric charge (Q) =?

We know, `I = Q/t`

Or, `Q = I xx t`

Or, `Q = 5 A xx 300 s = 1500 C`

Example 2: If a current of 2 ampere is drawn for 1 hour through the filament of a bulb, find the amount of electric charge flowing through the circuit.

Solution: Given, electric current (I) = 2 A

Time (t) = 1 hour `= 1 xx 60 xx 60 s = 3600 s`

Electric charge (Q) =?

We know that `Q = I xx t`

Therefore, `Q = 2 A xx 3600 s = 7200 C`

Example 3: In how much time 6000 coulomb of electric charge will flow, if an electric current of 10 A is drawn through an electric motor?

Solution: Given, electric charge (Q) = 6000 C

Electric current (I) = 10 A

Time (t) = ?

We know, `I = Q/t`

Or, `t = Q/I`

Or, `t = (6000 C)/(10 A) = 600 s`

Or, `t = 10` min

Example 4: If an electric charge of 900 C flows through an electric bulb for half an hour, find the electric current drawn by the filament.

Solution: Given, electric charge (Q) = 900 C

Time (t) = Half an hour = 30 m `= 30 xx 60 = 1800 s`

Electric current (I) =?

We know, `I = Q/t`

Or, `I = (900 C)/ (1800 s) = 0.5 A`

Example 5: If an electric charge of 1500 C flows through an electric iron for 5 minute, find the electric current drawn by filament of electric iron.

Solution: Given, electric charge (Q) = 1500 C

Time (t) = 5m `= 5 xx 60 = 300 s`

Electric current (I) =?

We know, `I = Q/t`

Or, `I = (1500 C)/(300 s) = 5 A`