MHT CET202210 Aug 2022Morning ShiftPhysicsAlternating CurrentActual
The primary and secondary voltage of an ideal step-down transformer is 200 ~V and 25 ~V respectively. The secondary is connected to a device, which draws a current of 2 ~A . The current in the primary is
Options
- A25 ~mA
- B42 ~mA
- C160 ~mA
- D250 ~mA
Correct answer
D. 250 ~mA
Step-by-step solution
For a lossless transformer, with primary coil (I_P, V_P ) and secondary coil (I_S, V_S ) , there has to be conservation of energy per unit time: aligned & I_P V_P=I_S V_S & I_P I_S = V_S V_P & I_P 2 = 25 500 & I_P= 1 4 ~A =250 ~mA aligned