An ideal transformer has 1000 turns on its primary and 50 turns on its secondary. The driving voltage in the primary side is 200 V (RMS) and load resistance is 5 Ohm. Calculate the input power.
An ideal transformer has 1000 turns on its primary and 50 turns on its secondary. The driving voltage in the primary side is 200 V (RMS) and load resistance is 5 Ohm. Calculate the input power.
Right Answer is:
20 W
SOLUTION
We have an ideal transformer with:
- Primary turns (N₁) = 1000
- Secondary turns (N₂) = 50
- Primary voltage (V₁) = 200 V (RMS)
- Load resistance (R₂) = 5 ohms
We need to calculate the input power.
Calculate Secondary Voltage (V₂):
In an ideal transformer
V₁/V₂ = N₁/N₂ V₂
= (N₂/N₁) * V₁ V₂ = (50/1000) * 200 = 10 V
Calculate Secondary Current (I₂):
Using Ohm’s law,
I₂ = V₂/R₂
I₂ = 10 V / 5 Ω = 2 A
Calculate Input Power (P₁):
In an ideal transformer, input power equals output power.
P₁ = P₂ = V₂ * I₂
P₁ = 10 V * 2 A = 20 W