Advertisements
Advertisements
प्रश्न
How are the e.m.f in the primary and secondary coils of a transformer related with the number of turns in these coils?
Advertisements
उत्तर
`"E"_"s"/"E"_"p" = "N"_"s"/"N"_"p"` = turns ratio n
where, s stands for secondary and p stands for primary.
i.e. `"E.M.f. in secondary coil"/"E.m.f. in primary coil" = "Number of turns in primary coil"/"Number of turns in secondary coil"`
APPEARS IN
संबंधित प्रश्न
How much current is drawn by the primary of a transformer connected to 220 V supply when it delivers power to a 110 V − 550 W refrigerator?
What type of current is transmitted from the power station?
State two ways through which the strength of an electromagnet can be increased.
The following diagram in Fig. 10.44 shows a coil X connected to a sensitive centre –zero galvanometer G and a coil P connected to a battery through a switch S.

(a) Describe the observation when the switch S is (i) closed suddenly, (ii) then kept closed, (iii) finally opened.
(b) Name and state the law which explains the above observations.
Draw a labelled diagram to show the various parts of a step-up transformer and step down transformer.
(i) Draw a clear labelled diagram of an electric bell.
(ii) Explain in brief, its working.
(iii) What material is used for the core of an electric bell? State the reason.
The primary coil of a transformer has 200 turns while the secondary coil has 1000 turns. What type of transformer is this? if the input voltage is 10V, what will be the output voltage?
A transformer lowers e.m.f. from 220 V to 15 V. If 400 W power is given in primary, calculate (i) the current in primary coil and (ii) the current in secondary coil.
The primary and secondary coils of a transformer each have an inductance of 200 x 10-6 H. The mutual inductance between the windings is 4 x 10-6 H. What percentage of the flux from one coil reaches the other?
