Advertisements
Advertisements
प्रश्न
A transformer is designed to work from a 240 V a.c. mains and to give a supply of 8 V to ring a house bell. The primary coil has 4800 turns. How many turns will be in the secondary coil?
A transformer is designed to give a supply of 8 V to ring a house-bell from the 240 V a.c. mains. The primary coil has 4800 turns. How many turns will be in the secondary coil?
उत्तर
Input ac voltage Vp = 240 V.
Number of turns in primary coil Np = 4800
No. of turns in secondary coil Ns = ?
Output voltage Vs = 8 V.
We know that
`"V"_"p"/"V"_"s" = "N"_"p"/"N"_"s"`
`"N"_"s" = ("N"_"p" xx "V"_"s")/ "V"_"p"`
= `(4800 xx 8) / 240`
= 160
The number of turns in the secondary coil is 160.
APPEARS IN
संबंधित प्रश्न
State the principle of a step-up transformer. Explain, with the help of a labeled diagram, its working ?
A transformer is used to step up an alternating emf of 200V to 440V. If the primary coil has 1000 turns, calculate the number of turns in the secondary coil.
An a.c generator generates an emf 'ε' where ε = 314 Sin (50πt) volt. Calculate the frequency of emf ε.
State the factors on which the frequency of the alternating e.m.f. depends.
Distinguish between Step up and Step Down Transformer.
A transformer is essentially an a.c. device. It cannot work on d.c. It changes alternating voltages or currents. It does not affect the frequency of a.c. It is based on the phenomenon of mutual induction. A transformer essentially consists of two coils of insulated copper wire having different numbers of turns and wound on the same soft iron core.
The number of turns in the primary and secondary coils of an ideal transformer is 2000 and 50 respectively. The primary coil is connected to a main supply of 120 V and secondary coil is connected to a bulb of resistance 0.6 Ω.
The value of current in the bulb is ______.
A transformer is used ______
In a transformer, number of turns in the primary coil are 140 and that in the secondary coil are 280. If current in primary coil is 4 A, then that in the secondary coil is ______.
The primary coil having NP turns of an ideal transformer is supplied with an alternating voltage VP. Obtain an expression for the voltage VS induced in its secondary coil having NS turns.
For what purpose are the transformers used?
