JAMB - Physics (1995 - No. 37)
The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be
3V
6V
24V
48V
Giải thích
\(\frac{V_s}{V_p}\) = \(\frac{N_s}{N_p}\) = \(\frac{I_p}{I_s}\)
\(\frac{100}{400}\) = \(\frac{V_S}{12}\)
V = 3V
\(\frac{100}{400}\) = \(\frac{V_S}{12}\)
V = 3V