A voltage of 20 V is required to cause a current of 2 A to flow in a resistor of resistance \( 10 \Omega \). What voltage would be required to make the same current flow if the resistance were \( 40 \Omega \)? [80V]

1. The relationship between voltage, current, and resistance is given by Ohm's Law: \[ V = IR \] 2. For the resistor with \( R = 10 \, \Omega \), the voltage required to produce a current of \( I = 2 \, \text{A} \) is: \[ V = (2 \, \text{A}) \times (10 \, \Omega) = 20 \, \text{V} \] 3. When the resistance is increased to \( R = 40 \, \Omega \), and the same current of \( 2 \, \text{A} \) is required, the new voltage is: \[ V = (2 \, \text{A}) \times (40 \, \Omega) = 80 \, \text{V} \] 4. Therefore, the voltage required to make the current of \( 2 \, \text{A} \) flow through a \( 40 \, \Omega \) resistor is \( 80 \, \text{V} \).