Question 15 of 31beginner💡 UnderstandMCQ1 mark

Which of the following terms does not represent electrical power in a circuit?

Exercise: EXERCISES | Q: 2 | (Page Page 23)
For More Understanding

Explanation

According to the textbook context, the electric power P is given by three valid formulas: P = VI, P = I²R, and P = V²/R. Option (A) I²R is a correct expression for power. Option (C) VI is the basic formula for power. Option (D) V²/R is also a correct expression derived from Ohm's law substitution. However, Option (B) IR² is not a valid formula for electrical power. The correct expression is I²R (current squared times resistance), not IR² (current times resistance squared). This is a common error students make by mixing up the position of the exponent.

Solution Steps

  1. Step 1: Recall the standard formulas for electric power from the textbook: P = VI, P = I²R, and P = V²/R.

  2. Step 2: Compare each option with these valid formulas.

  3. Step 3: Identify that IR² is not among the valid power formulas - the correct expression is I²R, not IR².

  4. Step 4: Conclude that option (B) IR² does not represent electrical power.

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