The primary coil of an ideal step up transformer has 100 turns and transformation ratio is also 100. The input voltage and power are respectively 220 V and 1100w. Calculate
(a) number of turns in secodary
(b) current in primary
( c) voltage across secodary
(d) current in secondary
( e) power in secondary

Explanation

(i) Transformer is used to step up or step down ac voltage It is based on principle of mutual induction.

working : When alternating current surce is conneted to the ends of primary coil the current changes contimuously in the primary coil , due to which the magnetic flux linked with the secondary coil change continuously, therefore the alternating emf of same frequency is developed across the secondary
Let `N_(p)` be the number of turns in primary coil `N_(s)` the number of turns uin secondary coil and `phi ` the magnetic flux linked with each turn. We assume that there is no leakage of flux so that the flux linked with each turn of primary coil and secondary coil is the same .According to Faraday's laws the emf induced in the primary coil
`epsilon_(p) = N_(p) =(Delta phi)/( Delta t)`
and emf induced in the secondary coil
`epsilon _(s) = - N_(s) (Delta phi)/(Delta t)`
From (i) and (ii) `(epsilon_(s))/(epsilon_(p)) = (N_(s))/(N_(p))`
Various losses are (i) flux loss (ii) IIumming loss (iii) Copper loss (iv) Eddy current loss .
(ii) (a) Transformation ratio `K= (N_(s))/(N_(p))`
`rArr " " N_(s) =KN_(p) =100 xx 100 = 10 ,000`
(b) `V_(p) = 220 V , P_(in) =1100W`
` I_(p) =(P_(in))/(V_(p)) = (1100)/(220) =5A`
(c ) `(V_(s))/(V_(p))= K " " rArr " "V_(s) = KV_(p) = 100 xx 220 = 22000 V`
` (d ) k = (I_(p))/(I_(s )) rArr I_(s) = (I_(p))/(K) =(5)/(100)= 5A`
(e ) `P_("out ") =V_(s) I_(s) =22000 xx 05 =11000W.`