Question

The loss of energy due to hysteresis when 5 kg of iron is subjected for 1 hour to cyclic magnetic changes of frequency 25 cycles/sec, if the hysteresis loop represents a loss of \( 2.5 \times 10^3 \) erg cm\(^3\) cycle\(^{-1}\) and density of iron is 7.8 gm cm\(^{-3}\), is:

• A. \(1.14 \times 10^3\) J
• B. \(1.24 \times 10^3\) J
• C. \(1.34 \times 10^3\) J
• D. \(1.44 \times 10^3\) J

Hint:

Hysteresis energy loss is proportional to the **frequency of magnetic reversals** and **material density**.

Answer 1

The Correct Option is A

The total energy loss due to hysteresis per unit volume per cycle is:
\ \[ W = \text{Hysteresis loss per cycle} \times \text{density} \times \text{total volume} \times \text{frequency} \times \text{time} \] After substituting the given values and converting units, the total loss comes out to be:
\[ 1.14 \times 10^3 \text{ J}. \]