To determine which circuit will have the greatest electric current, we can use Ohm's Law, which states:
\[ I = \frac{V}{R} \]
Where:
- \( I \) is the current (in amperes),
- \( V \) is the voltage (in volts), and
- \( R \) is the resistance (in ohms).
Let's calculate the current for each circuit:
-
Circuit 1: \[ I_1 = \frac{20 , \text{V}}{0.5 , \Omega} = 40 , \text{A} \]
-
Circuit 2: \[ I_2 = \frac{40 , \text{V}}{0.5 , \Omega} = 80 , \text{A} \]
-
Circuit 3: \[ I_3 = \frac{40 , \text{V}}{0.25 , \Omega} = 160 , \text{A} \]
-
Circuit 4: \[ I_4 = \frac{60 , \text{V}}{0.25 , \Omega} = 240 , \text{A} \]
Now let's compare the currents:
- Circuit 1: 40 A
- Circuit 2: 80 A
- Circuit 3: 160 A
- Circuit 4: 240 A
The circuit with the greatest electric current is Circuit 4 with a current of 240 A.