Question

How can voltage increase but current decrease?

Answer 1

Voltage can increase while current decreases in certain situations, especially when you are dealing with **resistance** and **power** in an electrical circuit. Here’s how:

1. **Ohm’s Law**: Ohm’s Law states that:

   \[
   V = I \times R
   \]

   where:
   - \( V \) is the voltage,
   - \( I \) is the current, and
   - \( R \) is the resistance.

   If the resistance \( R \) in the circuit increases, and the voltage \( V \) is also increased, the current \( I \) can still decrease if the resistance increases more than the voltage. For example, if you increase the voltage and the resistance increases, the current may drop.

2. **Power Transmission**: In power transmission systems, voltage is increased (stepped up using transformers) to reduce the current over long distances. This is because power loss in transmission lines is proportional to the square of the current (P = I²R), so by increasing voltage, the current decreases, reducing power loss.

3. **Load Characteristics**: In some electronic circuits (like in resistive loads or devices), when the voltage increases, the load might absorb less current if the impedance (resistance or opposition to current flow) increases, leading to a decrease in current.

In simple terms, voltage can increase, but the current may decrease if there is more resistance or impedance in the circuit to limit the flow of current. This is why in high-voltage power lines, we see high voltage and low current to minimize energy loss over long distances.