Which of the following types of transformer is used to step voltage up for transmission?

• A. Step-down transformer
• B. Step-up transformer
• C. Isolation transformer
• D. Auto transformer

Answer: (B)

Verified step by step guidance

1. Understand the purpose of transformers in electrical circuits: transformers are devices that change the voltage level of alternating current (AC) electricity without changing its frequency.
2. Recall that a step-up transformer increases the voltage from the primary coil to the secondary coil, which is useful for transmitting electricity over long distances to reduce energy loss.
3. Recognize that a step-down transformer decreases the voltage, typically used to reduce high transmission voltages to safer, usable levels for homes and businesses.
4. Know that an isolation transformer is used to electrically isolate two circuits without changing the voltage level significantly.
5. Identify that an auto transformer has a single winding that acts as both primary and secondary, and can either step up or step down voltage but is not typically used for high voltage transmission stepping up.