If 0.5 kg of this material is used in a transformer core, how long would it have to operate at a frequency of 60 cps to heat up 1

Respuesta :

Answer:

Hello your question is incomplete attached below is the complete question

answer : 49 seconds

Explanation:

considering only Hysteresis loss

we have to calculate the Area affected/under the  Hysteresis loss

= volume * area

= 4 * ( 1.5 * 20 ) =  120 tesla. A/m

next we calculate the volume of the material

= mass of material / density

= 500 grams / 7.9 g/cm^3  = 6.33 * 10^-5 m^3

next we calculate the heat lost per cycle

= 6.33 * 10^-5 m^3 * 120 = 0.007596 joules

The total heat required to raise  temperature by 1°c

= Cp * ΔT * n

= 3R * n * ΔT  = 3(8.314) * 8.95 * 1  = 223.23 Joules

where n = number of moles = 500grams / 55.85 = 8.95moles

ΔT = 1

Therefore the time required to have to operate at a frequency of 60 cps

= Total heat required  / heat lost per cycle

=( 223.23 / 0.007596 ) 60 cps

= 489.796 seconds ≈  49 seconds

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