Voltage and loops of transformers – problems and solution

1.

Based on the above table, find R and P.

Solution

Transformer’s equation :

V_s N_p = N_s V_p and V_p I_p = V_s I_s

V_s = secondary voltage, V_p = primary voltage, N_s = secondary loops, N_p = primary loops_, I_p = primary current, I_s = secondary current

Primary voltage (V_p)

V_p I_p = V_s I_s

V_p (4) = (10)(80)

V_p = 800 / 4

V_p = R = 200 Volt

Secondary loops (N_s)

V_s N_p = N_s V_p

(10)(600) = N_s (200)

6000 = 200 N_s

N_s = 6000 / 200

N_s = P = 30 loops

2.

Based on the above table, find K and L.

Solution :

Secondary current (I_s) of transformer 1 :

V_p I_p = V_s I_s

(200)(3) = (300)(I_s)

I_s = 600 / 300

I_s = K = 2 A

Secondary voltage (V_s) of transformer 2 :

V_p I_p = V_s I_s

(40)(0,75) = V_s (1)

V_s = L = 30 Volt

3.

Based on the table above, find P and Q.

Solution :

Primary voltage (V_p)

V_s N_p = N_s V_p

(220)(300) = (600) V_p

(220)(3) = (6) V_p

660 = 6 V_p

V_p = 660 / 6

V_p = P = 110 Volt

Primary current (I_p)

V_p I_p = V_s I_s

(110)(I_p) = (220)(2)

(110)(I_p) = 440

I_p = 440 / 110

I_p = Q = 4 A