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प्रश्न
Distinguish between Step up and Step Down Transformer.
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उत्तर
| No. | Step-up transformer | Step-down transformer |
| i. | The number of turns in its secondary is more than that in its primary (NS > NP). | The number of turns in primary is greater than in secondary (NP > NS). |
| ii. | The alternating voltage across the ends of its secondary is more than that across its primary, i.e., eS > eP. | The alternating voltage across the ends of the primary is more than that across its secondary, i.e., eP > eS. |
| iii. | Transformer ratio K > 1. | Transformer ratio K < 1. |
| iv. | Primary coil made of thick wire. | Secondary coil made of thick wire. |
| v. | The secondary coil is made of thin wire. | The primary coil is made of thin wire. |
| vi. | Current through secondary is less than primary. | Current through primary is less than secondary. |
संबंधित प्रश्न
Derive an expression for e.m.f. and current in terms of turns ratio
Express the turn ratio in terms of voltages.
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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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Name two factors on which the magnitude of an induced e.m.f. in the secondary coil depends.
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(i) Describe the observation if the coil is rapidly moved.
(ii) How would the observation be altered if (a) the coil has twice as many turns (b the coil was made to move three times as fast?
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(b) Name and state the law which explains the above observations.
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(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.
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Mention the various energy losses in a transformer.
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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.
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The value of current in the bulb is ______.
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The value of current in primary coil is ______.
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Power in primary coil is ______.
Define a Transformer.
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A transformer is used ______
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Efficiency of transformer is the ratio of ______.
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The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.
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A 12 V, 60 W lamp is connected to 220 V AC via an ideal transformer. Find the primary current.
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?
