SSC JE Electrical 2019 with solution SET-1
What would the total loss of the 2kVA transformer corresponding to maximum efficiency be, provided the transformer has the iron of 150 W and full-load copper loss of 250W?
When variable loss becomes equal to the constant loss, efficiency is maximum. Losses = Pi + Pc Since copper loss is a variable loss therefore Losses = Pi + Pi = 2pi Thus at a maximum efficiency of this transformer total loss = 150 x 2 = 300 W
The self-inductance is given as L = μN2A/I L ∝ N2 where N is the number of turns of the solenoid A is the area of each turn of the coil l is the length of the solenoid and μ is the permeability constant L1/L2 = N21/N22 0.5/0.5 = N21/N22 N1/N2 = 1
The inductance of the coil is given by the relation L = Nφ/I Where N = number of turns = 50 φ = flux = 200μWb I = current = 8 A L = 50 × 200 × 10−6 ⁄ 8 L = 1.25 mH
EXAMIANS