Simple electricity problem
Favorites|Homepage
Subscriptions | sitemap
HOME > Physics > Simple electricity problem

Simple electricity problem

[From: ] [author: ] [Date: 11-05-04] [Hit: ]
. ► I = 0.......
A 75 W high intensity lamp has a resistance of 12 ohms when burning. The
lamp’s power comes from the secondary of a small transformer, the primary of
which is connected to a 120 V circuit.
What is the ratio of the number of turns on the secondary winding?
What is the minimum current through the primary when the lamp is on?

-
From P = V²/R ..
V = √(P*R) = √900 = 30V
Vs = 30V

Ns/Np = Vs/Vp = 1/4 ... ...► Ns = 1/4Np


120v * I = 75W
I = 75/120 .... .... ► I = 0.625 A
1
keywords: Simple,problem,electricity,Simple electricity problem
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .