Question

The ideal battery (emf, LaTeX: \varepsilon ε ) in the circuit shown has a terminal voltage of 12 V. The ideal ammeter reads 0.25 A. Assuming ideal wires with no resistance, what is the resistance of the resistor, R ? 3.0 LaTeX: \Omega Ω 48 LaTeX: \Omega Ω 4.0 LaTeX: \Omega Ω 12 LaTeX: \Omega

what is the average power dissipated by the resistor in the previous question?

4.0 w 4.8W 3.0W 12W

Answer 1

Answer 2

Calculations:

1. Finding the Resistance ($R$):

• Given:

• Terminal voltage ($V$) = 12 V

• Current ($I$) = 0.25 A

• Using Ohm's Law:

  $$R=\frac{V}{I}=\frac{12\text{ V}}{0.25\text{ A}}=48\mathrm{\Omega }$$

2. Finding the Average Power Dissipated ($P$):

• Using the power formula:

  $$P=I^{2}R=(0.25\text{ A}{)}^2\times 48\mathrm{\Omega }=0.0625\times 48=3.0\text{ W}$$

  Alternatively, using $P=VI$:

  $$P=12\text{ V}\times 0.25\text{ A}=3.0\text{ W}$$

Both methods confirm the power dissipated is 3.0 W .