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Q50 (NDA-II/2022) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Electricity and magnetism

A DC generator works on the principle of

Result
Your answer: —  ·  Correct: C
Explanation

A DC generator is an electrical machine that converts mechanical energy into direct electrical power. Its operation is fundamentally based on Faraday’s laws of electromagnetic induction. According to these laws, when a conductor moves within a magnetic field and cuts the magnetic lines of flux, an electromotive force (EMF) is induced in the conductor [2]. The magnitude of this induced EMF depends on the rate of change of the magnetic flux linkage. While the internal generation produces alternating current, a DC generator specifically utilizes a commutator and brushes to ensure the output current remains unidirectional. In contrast, Ohm’s law describes the relationship between voltage, current, and resistance in a circuit [1], and Joule’s law of heating explains the conversion of electrical energy into heat.

Sources

  1. [2] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > H = I2 > p. 189
  2. [1] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > Figure 11.3 > p. 176
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