Select the correct statement (s) w.r.t. charges:

Options

A. The aditive property of charge is not an obvisou property, but is related to the fact that charge is a scalar physical quanity.
B. Charge is invariant, i.e., its value is the same in different frames of reference having relative motion.
C. Charge is conserved for an electrically isolated system, this can be concluded from the scalar nature of charge.
D. Charge is conserved for an electrically isolated system this can't be concluded from scalar nature of charge.

Answer

To solve the problem of selecting the correct statements regarding charges, we will analyze each option based on the properties of electric charge.

### Step-by-Step Solution:

1. **Understand the Additive Property of Charge**:
- The additive property of charge states that the total charge of a system is the algebraic sum of all individual charges. For example, if we have charges Q1, Q2, -Q3, and -Q4, the net charge (Q_net) can be calculated as:
\[ Q_{net} = Q1 + Q2 - Q3 - Q4 \]
- This property is valid because charge is a scalar quantity, which allows us to add and subtract charges directly.

**Hint**: Remember that scalar quantities can be added algebraically without considering direction.

2. **Evaluate the Invariance of Charge**:
- The term "invariant" means that the quantity does not change regardless of the observer's frame of reference. In the case of electric charge, it remains constant even if the observer moves. Therefore, charge is indeed invariant.

**Hint**: Think about how physical quantities behave under different frames of reference; invariance means they stay the same.

3. **Assess Conservation of Charge**:
- The statement "Charge is conserved for an electrically isolated system" is true. Conservation of charge means that the total charge in an isolated system remains constant over time.
- However, the assertion that this conservation can be concluded solely from the scalar nature of charge is incorrect. Just because a quantity is scalar does not imply it is conserved. For example, distance is also a scalar but is not conserved.

**Hint**: Conservation laws often arise from fundamental principles, not just from the nature of the quantities involved.

4. **Final Evaluation of Options**:
- **Option 1**: Correct (Additive property of charge is due to its scalar nature).
- **Option 2**: Correct (Charge is invariant).
- **Option 3**: Incorrect (Conservation cannot be concluded solely from scalar nature).
- **Option 4**: Incorrect (Similar reasoning as option 3).

### Conclusion:
The correct statements regarding charges are:
- Option 1: Correct
- Option 2: Correct
- Option 3: Incorrect
- Option 4: Incorrect

Thus, the correct answers are **Option 1 and Option 2**.