Why a transformer cannot be used to step up D.C. voltage?
Question
Why a transformer cannot be used to step up D.C. voltage?
Solution
A transformer cannot be used to step up DC voltage due to the following reasons:
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Working Principle: The basic principle of operation of a transformer is Faraday's law of electromagnetic induction, which states that the amount of voltage transformed from one coil to another is directly proportional to the rate of change of flux. In simpler terms, a transformer works on the principle of mutual induction, which requires a changing magnetic field.
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DC Supply: Direct Current (DC) provides a constant flow of electricity. This means that when DC voltage is applied to a transformer, the magnetic field produced in the core is also constant.
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No Changing Magnetic Field: Since the magnetic field is constant in the case of DC supply, there is no change or variation in the magnetic field over time. This means there is no mutual induction, which is necessary for the transformer to work.
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Overheating: If DC is applied, due to the lack of change in the magnetic field, the transformer will act as a short circuit, causing it to draw excessive current which can lead to overheating and potentially damaging the transformer.
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No Output: Since there is no changing magnetic field with DC, there will be no induced voltage in the secondary coil of the transformer. This means that a transformer cannot step up or step down DC voltage.
In conclusion, a transformer cannot be used to step up DC voltage because it operates on the principle of a changing magnetic field, which is not present in DC supply.
Similar Questions
Transformers are an essential part of the National Grid. What are they used for?To convert electricity from from a.c. to d.c. and vice versaTo adjust the supply of electricity according to how much energy is needed at a given timeTo improve the efficiency with which electrical energy can be transmitted around the countryTo allow energy to be transferred from one energy store to another2What name is given to the type of transformer which allows for the potential difference (‘voltage’) at which electricity is delivered to be increased?A high voltage transformerA boost transformerA step-up transformerA jump-up transformer3A current of 0.5 kA is flowing through a cable of resistance 20 Ω. Calculate the power dissipated in the cable.5 × 106 W10 W10 kW5 W4There is a potential difference of 250 V across an electrical cable. Calculate the amount of energy dissipated in the cable when a current of 100 A flows through it for 10 seconds.25 J2.5 J25,000 J250,000 J5A high voltage power cable transmits electrical energy with an efficiency of 0.8. If 2 × 107 W of electrical power is supplied to one end of the cable, how much is transmitted to the opposite end?1.6 × 109 W4 × 106 W2.5 × 107 W1.6 × 107 W
A transformer can work when it is connected to a ac source. Comment.
Why do transformers work with AC and not DC?*1 pointElectromagnetic induction requires changing magnetic flux produced by AC.Electromagnetic induction requires changing magnetic flux produced by DC.AC produces a magnetic field but DC does not.DC is too high for transformer operation.
Explain, using Faraday’s law of induction, how the transformer steps down the voltage.
All of the following statements about transformers are true, except:Group of answer choicesTransformers have two coil windings.Transformers can convert low voltage to high voltage.Transformers can convert high amperage to low amperage.Transformers only operate if the input current stays the same.
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