Two physical quantities whose dimensions are not same, cannot be :

Options

A. multiplied with each other
B. divided
C. added or substracted in the same expression
D. added together

Answer

To solve the question, we need to analyze the operations that can be performed on two physical quantities with different dimensions.

### Step-by-Step Solution:

1. **Understanding Physical Quantities**:
- Physical quantities can have different dimensions. For example, velocity has the dimension of length (L) over time (T), while time has the dimension of time (T).

2. **Operations on Physical Quantities**:
- **Multiplication**: Two physical quantities can be multiplied regardless of their dimensions. For example, if we multiply velocity (L/T) by time (T), we get displacement (L).
- **Division**: Similar to multiplication, two quantities can be divided. For instance, dividing velocity (L/T) by time (T) gives us acceleration (L/T²).
- **Addition/Subtraction**: This is where the dimensional analysis becomes critical. Two quantities can only be added or subtracted if they have the same dimensions. For example, you can add two lengths or two times, but you cannot add velocity (L/T) and time (T) because they have different dimensions.

3. **Conclusion**:
- Therefore, the correct answer to the question is that two physical quantities whose dimensions are not the same cannot be added or subtracted in the same expression.

### Final Answer:
Two physical quantities whose dimensions are not the same cannot be added or subtracted.