All Exams Test series for 1 year @ ₹349 only
Question

The fundamental operating principle of a transformer is based on:

The correct answer is

electromagnetic induction between two electrically isolated coils magnetically coupled through a low-reluctance magnetic circuit

The fundamental operating principle of a transformer is based on electromagnetic induction. Let us go through a detailed explanation to understand why this is the principle and why other options do not apply.

  1. Electromagnetic Induction:
    • A transformer operates on the principle of electromagnetic induction, which involves the induction of an electromotive force (EMF) in a coil due to a changing magnetic field. This principle is applied between two electrically isolated coils known as the primary and secondary windings.
    • The primary coil, when connected to an AC source, creates a time-varying magnetic flux. This flux links with the secondary coil through a common magnetic core, often made of iron, which has a low reluctance to magnetic flux.
    • The changes in the magnetic field induce an alternating voltage across the secondary coil, facilitating energy transfer without direct electrical contact. This method is efficient and ensures safety through electrical isolation between the input (primary) and output (secondary) sides.
  2. Reasons Other Options Are Incorrect:
    • Direct Electrical Conduction: This is incorrect as transformers rely on electromagnetic induction, not direct electrical conduction between the windings, which would defeat the purpose of electrical isolation.
    • Mechanical Coupling: Transformers do not use any physical or mechanical means (like motion) for energy transfer, making this option irrelevant.
    • AC to DC Conversion: Transformers do not convert AC to DC; they only modify the voltage levels of AC. Rectifiers, not transformers, are used for AC to DC conversion.

Therefore, the correct answer is electromagnetic induction between two electrically isolated coils magnetically coupled through a low-reluctance magnetic circuit.

Was this answer helpful?

Similar Questions

  1. A 12μF capacitor and a 4μF capacitor are connected in series. The ratio of voltages across them will be:

  2. Which combination of the following statements about direct resistance heating are correct?

     i) The process requires the charge to be electrically conductive. 

    ii) Electrodes are placed in direct contact with the charge. 

    iii) Heat is generated by induced eddy currents in the charge. 

    iv) The charge does not form part of the electric circuit.

  3. In a single-phase RL circuit, the RMS voltage across the supply is 100 V, the RMS current is 5 A, and the current lags the voltage by 60°. Determine the apparent power of the circuit.

  4. Select the option that is correct regarding the following two statements labelled Assertion (A) and Reason (R). 

    Assertion (A): Three-phase auto-transformers are smaller and lighter than equivalent three-phase two-winding transformers. 

    Reason (R): Auto-transformers use fewer windings and a smaller core.


Important Questions from Transformer

  1. Which of the following is used in transformer protection system?

  2. Open circuit test on transformers is conducted to determine which of the following?

  3. ________ is a property of ferromagnetic materials that causes them to change their shape or dimensions during the process of magnetization.

  4. The transformation ratio ($K$) of a step-up transformer is:

  5. A transformer transforms

Need Expert Advice?
Test Series
RRB JE img
Railways
RRB JE Prev. Yr. Paper (CBT 1 + CBT 2) Test Series
290 Tests 5 Tests Free
4460 Attempts
4.3(88)
English

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App