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
Explain the construction and working of the transformer.
The input and output voltage of a transformer are 220 V and 44 V respectively. Find: the turns ratio.
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.
The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.
State whether true or false. If false, correct the statement.
A transformer can step up direct current.
What are step-up and step-down transformers?
Give the advantage of AC in long distance power transmission with an illustration.
For an LCR circuit, the power transferred from the driving source to the driven oscillator is P = I2Z cos φ.
- Here, the power factor cos φ ≥ 0, P ≥ 0.
- The driving force can give no energy to the oscillator (P = 0) in some cases.
- The driving force cannot syphon out (P < 0) the energy out of oscillator.
- The driving force can take away energy out of the oscillator.
An iron rod of 0.2 cm2 cross-sectional area is subjected to a magnetising field of 1200 Am-1. If the susceptibility of iron is 599, then the magnetic flux produced is ______.
Mention two main sources of power loss in real transformers.
