In transmission of power from generation plants to users, transformers are used. Identify the correct reason to choose appropriate transformers.

(A) A step-up transformer is used at the generation plant and high voltages are transmitted.
(B) A step-down transformer is used at the generation plant and low voltages are transmitted.
(C) A step-up transformer lowers the current and hence loss due to joule heating is less.
(D) A step-down transformer lowers the current and hence loss due to joule heating is less.

Choose the correct answer from the options given below:

(A) and (C) only

The correct answer is Option (1) → (A) and (C) only

In power transmission, power $P=VI$. For long-distance transmission, to reduce joule heating loss:

Power loss $=I^2R$

→ To minimize loss, current $I$ must be reduced. → This is achieved by increasing voltage $V$ using a step-up transformer at the generation plant. → At the consumer end, a step-down transformer reduces the voltage to a safe level.

Therefore, the correct statements are:

(A) A step-up transformer is used at the generation plant and high voltages are transmitted.

(C) A step-up transformer lowers the current and hence loss due to joule heating is less.

Final Answer: (A) and (C)