Physics · Electrical energy and power, electrical resistivity and conductivity

In the circuit shown, the heat produced in resistor is 10 calorie/sec. The heat

In the circuit shown, the heat produced in \( 5 \Omega \) resistor is 10 calorie/sec. The heat produced/sec in \( 4 \Omega \) resistor will be :

  • A. 1 cal
  • B. 2 cal
  • C. 3 \) cal
  • D. 4 cal

Step-by-step solution

The heat produced in a resistor is proportional to the square of the current through it (P = I²R). Given that the heat in the 5 Ω resistor is 10 cal/s, we have I₅² × 5 = 10, so I₅² = 2. If the circuit is arranged such that the current through the 4 Ω resistor is half that through the 5 Ω resistor (e.g., via a parallel combination with appropriate series resistors), then I₄² = (I₅/2)² = I₅²/4 = 0.5, and the heat in the 4 Ω resistor is I₄² × 4 = 0.5 × 4 = 2 cal/s.
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