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प्रश्न
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.
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उत्तर
(i) We know that Power = Ip × Ep
or 400 = Ip × 220
∴ Ip = 1.8 A
(ii) Using Ip × Ep = Is × Es
∴ `"I"_"s" = ("I"_"p" xx "E"_"p")/"E"_"s"`
`"I"_"s" = (1.8 xx 220)/15`
= 26.4 A.
संबंधित प्रश्न
Complete the following sentence :
……… energy is converted into …………energy by an electric motor.
Explain the significance of Lenz’s law to show the conservation of energy in electromagnetic induction.
Mention the two characteristic properties of the material suitable for making core of a transformer.
The power supply to the primary coil of a transformer is 200 W. Find
(i) Current in primary coil if the e.m.f. supply to it is equal to 220V.
(ii) The number of turns in the primary coil is equal to 80 and that in secondary is 800. What is the transformation ratio?
(iii) Name the type of transformer.
(iv) What will be the output voltage?
(v) What is the current in the secondary coil for an ideal transformer?
(vi) What is the output power?
(vii) Is output and input power equal?
(viii) Compare the current flowing in a secondary coil and in a primary coil.
Give the advantage of AC in long distance power transmission with an illustration.
A step-down transformer connected to the main supply of 220 V is used to operate 11V,88W lamp. Calculate
- Voltage transformation ratio and
- Current in the primary
For what purpose are the transformers used?
A step down transformer connected to an AC mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?
In an ideal transformer, the turns ratio is `N_p/N_s = 1/2`. The ratio Vs : Vp is equal to (the symbols carry their usual meaning):
Which law relates the changing flux to the EMF induced in both coils?
