1.

The number of turns in the primary and secondary coils of an ideal transformer are 2000 and 50 respectively. The primary coil is conneted to a main supply of 120 V and socondary to a night bulb of `0.6 Omega`. Calculate (i) Voltage acorss the secondary. (ii) Current in the bulb, (iii) Current in primarya coil, (iv) Power in primary and secondary coils, (iv) Power in primary and secondary coils.

Answer» Here, `n_(p) = 2000, n_(s) = 50`,
`E_(p) = 120 V , R_(s) = 0.6 Omega`
`E_(s) = ?, I_(s) = ?, I_(p) = ?, P_(p) = ?, P_(s) = ?`
(i) As `(E_(s))/(E_(p)) = (n_(s))/(n_(p))`
`:. E_(s) = E_(p) . (n_(s))/(n_(p)) = 120 xx (50)/(2000) = 3 V`
(ii) As `I_(s) = (E_(s))/(R ) :. I_(s) = (3)/(0.6) = 5 A` (iii) As `(I_(p))/(I_(s)) = (E_(s))/(E_(p))`
`:. I_(p) = (E_(s))/( E_(p)) xx I_(s) = (3)/(120) xx 5 = 0.125 A`
(iv) Power in primary,
`P_(p) = E_(p) xx I_(p) = 120 xx 0.125 = 15 W`
Power in secondary, `P_(s) = E_(s) xx I_(s) = 3 xx 5 = 15 W`


Discussion

No Comment Found

Related InterviewSolutions