Consider the following statements: (i) Any dc-generator can also function as a simple dc-motor. (ii) The induced electromotive force produced in an AC Generator reverses direction twice per period. Choose the correct option:

Question

Accepted Answer

Explanation:

1. **Statement (i): Any dc-generator can also function as a simple dc-motor.**

This statement is correct. A DC generator and a DC motor are fundamentally similar in construction. Both devices consist of a rotor (armature), a stator (field windings or permanent magnets), a commutator, and brushes. The primary difference lies in their operation: a DC generator converts mechanical energy into electrical energy, while a DC motor converts electrical energy into mechanical energy. Due to their similar construction, a DC generator can function as a DC motor when electrical energy is supplied to it, causing the armature to rotate. This interchangeability is a well-known principle in electromechanical systems.

2. **Statement (ii): The induced electromotive force produced in an AC Generator reverses direction twice per period.**

This statement is also correct. An AC generator, or alternator, produces an alternating current (AC) by rotating a coil within a magnetic field. As the coil rotates, the direction of the induced electromotive force (EMF) changes due to the alternating nature of the magnetic flux linkage. In one complete cycle of rotation (one period), the EMF reaches a positive peak, returns to zero, reaches a negative peak, and returns to zero again. This results in the EMF reversing direction twice per period, which is characteristic of AC waveforms.

Given that both statements (i) and (ii) are correct, Option 4, which states that both statements are correct, is the correct answer.

**Why the other options are incorrect:**

- **Option 1: Only (i) is correct.** This option is incorrect because it disregards the correctness of statement (ii), which accurately describes the behavior of the induced EMF in an AC generator.

- **Option 2: Only (ii) is correct.** This option is incorrect because it ignores the validity of statement (i), which correctly explains the functional interchangeability of DC generators and motors.

- **Option 3: Both (i) and (ii) are incorrect.** This option is incorrect because both statements are factually accurate, as explained above.

Therefore, the correct answer is Option 4, as both statements are indeed correct.