Question

A transformer consists of a 500-turn primary coil and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current in the primary

Answer 1

12A

Step-by-step explanation:

Formula for calculating the relationship between the electromotive force (emf), current and number of turns of a coil in a transformer is expressed as shown:

`(V_s)/(V_p) = (N_s)/(N_p) = (I_p)/(I_s)` where;

Vs and Vp are the emf in the secondary and primary coil respectively

Ns and Np are the number if turns in the secondary and primary coil respectively

Ip and Is are the currents in the secondary and primary coil respectively

Since the are all equal to each other, then we can equate any teo of the expression as shown;

`(N_s)/(N_p) = (I_p)/(I_s)`

Given parameters

Np = 500-turns

Ns = 2000-turns

Is = 3.0Amp

Required

Current in the primary coil (Ip)

Using the relationship
`(N_s)/(N_p) = (I_p)/(I_s)`

`I_p = (N_sI_s)/(N_p)`

`I_p = (2000*3)/(500) \\\\I_p = (6000)/(500)\\ \\I_p = 12A\\`

Hence the current in the primary coil is 12Amp