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प्रश्न
The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage and power are 220 V and 1100 W, respectively. Calculate the
(a) number of turns in secondary
(b) current in the primary
(c) a voltage across secondary
(d) current in secondary
(e) power in secondary
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उत्तर
(a) Number of turns in secondary coil is given by
`N_S/N_P=n`
`=>N_S/100=100`
⇒NS=10,000
(b) Current in primary is given by
IPVP=P
`=>I_P=1100/220=5A`
(c) Voltage across secondary is given by
`V_S/V_P=N_S/N_P=n`
⇒VS=100×220=22,000 V
(d) Current in secondary is given by
VSIS=P
`=>I_S=P/V_S=1100/22000=0.05A`
(e) Power in secondary is power in primary in an ideal transformer.
= 1,100 W
संबंधित प्रश्न
Mention various energy losses in transformer device
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1) Name the device used to change the alternating voltage to a higher or lower value. State one cause for power dissipation in this device.
2) Explain with an example, how power loss is reduced if the energy is transmitted over long distances as an alternating current rather than a direct current.
3) Write two values each shown by the teachers and Geeta.
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Read the following paragraph and answer the question:

Long distance power transmissions
The large-scale transmission and distribution of electrical energy over long distances is done with the use of transformers. The voltage output of the generator is stepped up. It is then transmitted over long distances to an area sub-station near the consumers. There the voltage is stepped down. It is further stepped down at distributing sub-stations and utility poles before a power supply of 240 V reaches our homes.
A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns. The number of turns in the secondary in order to get output power at 230 V are ______.
An ideal transformer converts 170 V a.c. to 1.70 KV a.c. to transmit a power of 3.4 KW. If primary coil has 500 turns then alternating current in secondary coil is ______.
