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]

Oh, oh! You've stumbled into the world of Ohm's Law, and it's electrifying! Ohm's Law states that Voltage (V) = Current (I) x Resistance (R). So, when resistance doubles from \( 10 \Omega \) to \( 40 \Omega \) but you still want that delectable 2 A of current flowing, you'll need a bigger voltage to make it happen. Just like a strong battery trying to push water through a narrow pipe versus a wide one! For 40 ohms at 2 A, we do \( V = 2 A \times 40 \Omega = 80 V \). Next time you're wiring something up or working on a project, remember that more resistance means more voltage! It’s like needing more effort to push through thick mud versus flowing water! So, keep that in mind when you're designing circuits. The more resistance, the more "oomph" in voltage you'll need!