The convert an AC generator into DC generator:

Options

A. split ring type commutator must be used
B. slip rigs and brushes must be used
C. a stornger magnetic field has to be used
D. a rectangular wire loop has to be used

Explanation

To convert an AC generator into a DC generator, we need to make specific modifications to the generator's design. Here’s a step-by-step solution to understand how this conversion is achieved:

### Step 1: Understand the Current Types
- **AC Generator**: Produces alternating current (AC), where the current changes direction periodically.
- **DC Generator**: Produces direct current (DC), where the current flows in one direction only.

### Step 2: Identify the Components
- An AC generator typically uses **slip rings** to connect the rotating coil to the external circuit. These slip rings allow the current to alternate as the coil rotates.
- A DC generator uses a **commutator**, specifically a **split ring type commutator**, to ensure that the current flows in one direction.

### Step 3: Replace Slip Rings with Commutator
- To convert an AC generator into a DC generator, we need to replace the slip rings with a split ring type commutator.
- The split ring commutator consists of two halves that are connected to the ends of the coil. As the coil rotates, the commutator reverses the connection to the external circuit at the appropriate times, ensuring that the current always flows in the same direction.

### Step 4: Function of the Split Ring Commutator
- As the coil rotates, when one side of the coil moves from the upward position to the downward position, the commutator switches the connection so that the current direction remains constant.
- This switching action prevents the current from alternating, effectively converting the AC output into a DC output.

### Step 5: Conclusion
- Therefore, to convert an AC generator into a DC generator, the correct modification is to use a **split ring type commutator** instead of slip rings.

### Final Answer
The correct answer is: **A split ring type commutator must be used.**

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