Question

The accompanying figure shows some electrical appliances connected in a circuit in a house. Answer the following questions.

A. By which method are the appliances connected?

B. What must be the potential difference across individual appliances?

C. Will the current passing through each appliance be the same? Justify your answer.

D. Why are the domestic appliances connected in this way?

E. If the T.V. stops working, will the other appliances also stop working? Explain your answer.

Answer 1

A. The appliances are connected in parallel.

B. The potential difference across each appliance should be same as they are connected in parallel. The potential difference between live and neutral wire in domestic wiring is maintained at 220 V in India. Hence, the potential difference across each appliance should be 220 V.

C. No, the current passing through each appliance is not same. From Ohm's law, the current flowing through each appliance is given as
$I=\frac{V}{R}$
Since, potential difference across each appliance is same, thus
$I\propto \frac{1}{R}$
Now, each appliance has different value of resistance. Thus, the current flowing through them will be different. The one with greater value of resistance will receive lesser amount of current and the one with less value of resistance will receive more current.

D. Domestic appliance are connected in parallel because this connection assures that even if one or more appliances get faulty or stops working, the working of others will remain unaffected.

E. The working of other appliances will remain unaffected even if the T.V. stops working. The current through T.V. will stop but the other appliances will receive the approximately the same amount of current as before. This is because in parallel connection, the current divides itself in the number of electrical branches present. If one of the branches becomes open circuited due to some fault, the remaining branches will still be forming complete circuit for the flow of current.