Chapter 21, Problem 27P

To determine

(a)

The type of transformer

Answer to Problem 27P

Solution:

It is a step-down transformer

Explanation of Solution

Given info:

No. of turns in primary coil $\left(N_p\right)\text{=360}$

No. of turns in secondary coil $\left(N_s\right)\text{=120}$

A transformer designed to reduced voltage from primary coil to secondary coil is called a step-down transformer. This is step down transformer because Ns<Np (or)Np>Ns.

To determine

(b)

The change in voltage

Answer to Problem 27P

Solution:

Voltage changes by $1:3$ ratio.

Explanation of Solution

Given info:

No. of turns in primary coil $\left(N_p\right)\text{=360}$

No. of turns in secondary coil $\left(N_s\right)\text{=120}$

Formula used:

According to voltage ratio formula

$\frac{N_p}{N_s}=\frac{V_p}{V_s}$

Calculation:

$\Rightarrow \frac{V_s}{V_p}=\frac{120}{360}$

$=\frac{1}{3}$

To determine

(c)

Change in current

Answer to Problem 27P

Solution:

Change in current by $3:1$ ratio.

Explanation of Solution

Given info:

No. of turns in primary coil $\left(N_p\right)\text{=360}$

No. of turns in secondary coil $\left(N_s\right)\text{=120}$

Formula used:

According to current ratio formula

$\frac{N_p}{N_s}=\frac{I_s}{I_p}$

Calculation:

$\Rightarrow \frac{I_s}{I_p}=\frac{360}{120}$

$=\text{3 A}$