A : The ammeters and volmetrs used for measuring alternating current and voltages have non-uniform divisons on their scales.
R : The instruments used for measuring alternating current and voltage are based on heating effect of current.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false, then mark (3)
D. If both Assertion and Reason are false statement, then mark (4)

Answer

To solve the assertion-reason question, we need to analyze both the assertion (A) and the reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states that "The ammeters and voltmeters used for measuring alternating current and voltages have non-uniform divisions on their scales."

- **Explanation**: This is true because the relationship between the current (I) and the heating effect (which is proportional to I²) is not linear. As current increases, the heating effect increases with the square of the current, leading to a non-linear scale. Therefore, the divisions on the scale of these instruments are not uniform.

### Step 2: Analyze the Reason (R)
The reason states that "The instruments used for measuring alternating current and voltage are based on the heating effect of current."

- **Explanation**: This is also true. The heating effect of current is utilized in ammeters and voltmeters to measure AC because the heating effect is proportional to the square of the current (I²). This means that even though AC current changes direction, the heating effect remains positive and can be measured effectively.

### Step 3: Establish the Relationship Between A and R
Now we need to determine if the reason correctly explains the assertion.

- **Explanation**: The reason does explain the assertion because the non-uniformity of the scale divisions arises from the fact that the heating effect is proportional to I². Since I² does not increase uniformly, the scale divisions must also reflect this non-uniformity.

### Conclusion
Both the assertion and the reason are true, and the reason is the correct explanation for the assertion.

### Final Answer
- **Assertion (A)**: True
- **Reason (R)**: True
- **Explanation**: R is the correct explanation for A.

---