Question

Which of the following statements are true regarding transformers?Check all that apply.

In a transformer, if the primary coil contains more loops than the secondary coil, then it is a step-up transformer.A transformer converts mechanical energy into electrical energy.A transformer is used to increase or decrease a direct current voltage.A transformer is used to increase or decrease an alternating current voltage.In a transformer, if the secondary coil contains more loops than the primary coil, then it is a step-up transformer.In a transformer, the power input is less than the power output.

Answer 1

In a transformer, if the secondary coil contains more loops than the primary coil, then it is a step-up transformer.

Step-by-step explanation:

• A transformer is made up of primary coil and secondary coil. when the number of loops in the secondary coil is less than the primary coil, the transformer is called step down transformer.
• Also if the number of loops in the secondary coil is more than the primary coil, then it is called a step-up transformer. In a step-up transformer the voltage output will be greater.

Answer 2

There are two correct options.

1. A transformer is used to increase or decrease an alternating current voltage.

2. In a transformer, if the secondary coil contains more loops than the primary coil, then it is a step-up transformer.

Step-by-step explanation:

A transformer is a device which has two coils. One is primary coil and other is secondary coil.

Input is given to primary coil and output is taken out from secondary coil.

A transformer can increase or decrease the output voltage by setting the number of turns in primary and secondary coil.

If the number of turns in primary coil is less than the number of turns in secondary coil, then it is step up transformer. It increases the output voltage.

The relation between the number of turns and the voltage is given by

`(N_(s))/(N_(p))=(V_(s))/(V_(p))=(I_(p))/(I_(s))`

Where, Np = number of turns in primary coil

Ns = number of turns in secondary coil

Vp = ac voltage across primary coil

Vs = ac voltage across secondary coil

Ip = ac current across primary coil

Is = ac current across secondary coil