Question

The DC power source for arc welding has the characteristics \( 3V + I = 240 \), where 'V' is the voltage in volts and 'I' is the current in amperes. For maximum power at the electrode, voltage should be set at:

• A. 40 V
• B. 140 V
• C. 220 V
• D. 240 V

Hint:

To maximize power in electrical systems, the voltage and current must be chosen to balance the equation \( P = V \times I \).

Answer 1

The Correct Option is B

Step 1: Power Equation Application.
The power \( P \) is defined as:\[P = V \times I\]The voltage and current relationship is described by:\[3V + I = 240\]Step 2: Power Maximization To maximize power, determine the voltage and current values that yield the maximum \( P = V \times I \). This occurs when \( \frac{dP}{dV} = 0 \).Step 3: Result The optimal voltage derived from solving the equation is \( 140 \, \text{V} \). Final Answer: \[ \boxed{140 \, \text{V}}\]