Question

A power transmission line feeds input power at 2400 V to a step down transformer with its primary windings

having 4000 turns. What should be the number of turns in the secondary windings in order to get output power

t 240 V?

• A. 400
• B. 420
• C. 424
• D. 436

Answer 1

Answer: (A)

400

Answer 2

: Here,

$V_{P} = 2400V,N_{P} = 4000,V_{s} = 240V$

As $\frac{V_{s}}{V_{P}} = \frac{N_{s}}{N_{P}}$

$\therefore N_{s} = \left( \frac{V_{s}}{V_{P}} \right)N_{P} = \frac{240}{2400} \times 4000 = 400$