Keiko builds a transformer in the lab, but it does not decrease the voltage as much as she needs. What should Keiko change to further reduce the voltage?

She should increase the number of coils in the primary winding.

Explanation:

A transformer is an electrical apparatus that transfers electrical energy from one electrical circuit to another through mutual electromagnetic induction.

The main purpose of transformer is to increase or decrease (alternating current (AC)) voltage in circuits.

In its structure there are 2 coils:

Primary coil Secondary coil.

For decreasing voltage, ration of number of turns in coil of primary to secondary coil should big.

So to further reduce the voltage, she should increase the number of coils in the primary winding.

Answer

D. She should increase the number of coils in the primary winding.

Explanation

A transformer is a device that is used to step down or step up a the voltage.

It has two coils, primary and secondary that are used to determine how much the voltage changes.

To decrease the voltage the ratio of number of coils in the primary to the number of coils in the secondary should be big.

To reduce the voltage, D. She should increase the number of coils in the primary winding.