Correct Option
The correct option is It increases.
Explanation
Domestic electrical circuits are wired in parallel. This arrangement ensures that every appliance operates at the same rated voltage (e.g., 220V in India) and functions independently of others. In a parallel circuit, the total current drawn from the source is the sum of the individual currents flowing through each branch.
Detailed Analysis
When an additional appliance is connected in parallel across a constant-voltage supply, the circuit parameters change as follows:
- Voltage Stability: The potential difference across the new appliance is the same as the source voltage, consistent with parallel circuit properties.
- Current Addition: The new appliance provides an additional path for the flow of charge. It draws a specific amount of current (\(I_{new}\)) determined by its resistance and the supply voltage (\(I = V/R\)).
- Total Current: The total current drawn from the source is the sum of currents in all branches (\(I_{total} = I_1 + I_2 + \dots + I_{new}\)). Since the new appliance draws a non-zero current, the total current increases.
- Equivalent Resistance: Mathematically, adding a resistor in parallel decreases the equivalent resistance (\(R_{eq}\)) of the entire circuit. According to Ohm’s Law (\(I = V/R_{eq}\)), for a constant voltage \(V\), a decrease in \(R_{eq}\) results in an increase in total current \(I\).
Key Takeaway: Connecting devices in parallel decreases the overall resistance of the circuit and increases the total current drawn from the voltage source, as each device draws its own current independently.