What is the voltage across a 10-ohm resistor if a current of 2 amperes flows through it?

• A. 10 volts
• B. 20 volts
• C. 15 volts
• D. 25 volts

Answer: (B)

The correct answer is 20 volts because the voltage across a resistor can be calculated using Ohm's Law, which states that voltage (V) equals current (I) multiplied by resistance (R). In this case, with a resistance of 10 ohms and a current of 2 amperes flowing through the resistor, the calculation is as follows:

V = I × R

V = 2 A × 10 Ω

V = 20 V

This calculation shows that the voltage across the resistor is indeed 20 volts. Understanding Ohm's Law is essential for working with electrical circuits, as it allows you to determine the relationship between voltage, current, and resistance.