Question

a power transmission line feeds input power at 2400 v to a step-down transformer and which delivers power at 240 v with its primary windings having 5000 turns. if the current in the primary coil of the transformer is 5 a and its efficiency is 80 % , then what is the output current (in a )?

Answer 1

To determine the output current of the step-down transformer, we can use the formula:

Input power (P₁) = Output power (P₂)

The power in a circuit is given by the formula:

Power (P) = Voltage (V) * Current (I)

We are given the following information:

Input voltage (V₁) = 2400 V

Output voltage (V₂) = 240 V

Current in the primary coil (I₁) = 5 A

Efficiency of the transformer = 80% = 0.8 (decimal form)

First, let's calculate the input power:

P₁ = V₁ * I₁

P₁ = 2400 V * 5 A

P₁ = 12000 VA

Since the efficiency of the transformer is given as 80%, the output power can be calculated as:

P₂ = η * P₁

P₂ = 0.8 * 12000 VA

P₂ = 9600 VA

Now, let's calculate the output current (I₂):

P₂ = V₂ * I₂

I₂ = P₂ / V₂

I₂ = 9600 VA / 240 V

I₂ = 40 A

Therefore, the output current of the transformer is 40 A.