To modify the magnitude of an alternating voltage without altering its frequency, which principle is applied in the functioning of a transformer?
Show answer & explanation
Correct answer: C
Explanation
Correct Answer:-
Mutual induction
Explanation:-
A transformer operates on the principle of 'Mutual induction.' When alternating current (AC) flows through the primary coil, it creates a changing magnetic field. According to Faraday's law of electromagnetic induction, this changing magnetic flux links with the secondary coil, inducing an electromotive force (EMF) in it. Through this process, the voltage level can be increased or decreased while the frequency of the power remains unchanged.
Self-induction occurs when the current change within a single coil induces an EMF in that same coil, whereas a transformer relies on the magnetic coupling between two separate coils. Other options, such as capacitive coupling or electromagnetic radiation, are not the fundamental working principles of a standard power transformer.
Key Points
Transformers function exclusively with alternating current (AC) and do not work with direct current (DC). They adhere to the principle of energy conservation, where, in an ideal scenario, the input power equals the output power. 'Step-up' transformers are utilized to increase voltage, while 'step-down' transformers are employed to decrease it.
Important Questions and Answers
Question: What is the core used in a transformer made of?
Answer: It is made of laminated sheets of soft iron to minimize energy loss caused by eddy currents.
Question: What is the primary function of a transformer?
Answer: Its main function is to increase or decrease the voltage level of electrical power without altering its frequency.