Question

Consider two resistors connected in parallel and attached to a voltage source ofV. If a thirdresistor is added in parallel to the other two, how does the power dissipated by one of the original resistorschange? Using that fact, why do you think houses use parallel circuits?

Answer 1

Answer:

Explanation:

Let assume the first connect have resistor R1 and R2

Then, this are connected in parallel

But, parallel connection of resistor have the same voltage.

So the power dissipated in each resistor is given as

P1=V²/R1

P2= V²/R2

If another resistor is added in parallel nothing change by the way each resistor dissipate power

Then, power dissipated in R3 is

P=V²/R3

Why we use parallel circuit at home

Parallel circuits are used in homes because the loads can be operated independently of each other.

Each load gets the full voltage of the circuit.

Answer 2

Explanation:

Resistors in parallel :

When resistors are connected in parallel, same voltage appears across each resistor in the circuit. The current is divided between resistors in a parallel circuit depending upon its resistance. If resistance is low then high current flows through it and vice versa.

Let us assume the three resistors are R₁, R₂, and R₃  

The power dissipated across each resistor is given by

P₁ = V²/R₁

P₂ = V²/R₂

P₃ = V²/R₃

Why parallel connection in house wiring?

We use parallel connection in house wiring so that each device gets same line voltage (120V, 220V, 240V etc ) and the devices are independently connected or disconnected from the circuit without affecting any other device.

This is not possible in case of series circuit, where each device would get reduced voltage due overall higher resistance.

As the number of devices increases the voltage across each device also increases.

If one device malfunctions then other devices in the series circuit would be compromised hence poor reliability.