Which of the following sets have different dimensions ?

Options

A. Pressure ,Young's modulus, Stress
B. Enf potential difference.Electric potential
C. Heat, Work done .Energy
D. Dipole moment .Electric flux .Electric field

Explanation

To solve the question of which of the following sets have different dimensions, we will analyze each set of terms provided in the question.

### Step-by-Step Solution:

1. **Identify the Terms**:
We have four sets of terms to analyze:
- Set 1: Pressure, Young's Modulus, Stress
- Set 2: EMF, Potential Difference, Electric Potential
- Set 3: Heat, Work, Energy
- Set 4: Dipole Moment, Electric Flux, Electric Field

2. **Analyze Set 1: Pressure, Young's Modulus, Stress**:
- **Pressure**: Defined as force per unit area.
\[ \text{Dimension of Pressure} = \frac{[F]}{[A]} = \frac{M^1 L^1 T^{-2}}{L^2} = M^1 L^{-1} T^{-2} \]
- **Stress**: Also defined as force per unit area.
\[ \text{Dimension of Stress} = \frac{[F]}{[A]} = M^1 L^{-1} T^{-2} \]
- **Young's Modulus**: Defined as stress divided by strain. Since strain is dimensionless, Young's Modulus has the same dimension as stress.
\[ \text{Dimension of Young's Modulus} = M^1 L^{-1} T^{-2} \]
- **Conclusion**: All three have the same dimensions.

3. **Analyze Set 2: EMF, Potential Difference, Electric Potential**:
- **EMF**: Defined as work done per unit charge.
\[ \text{Dimension of EMF} = \frac{[W]}{[Q]} = \frac{M^1 L^2 T^{-2}}{A T} = M^1 L^2 T^{-3} A^{-1} \]
- **Potential Difference**: Same as EMF, work done per unit charge.
\[ \text{Dimension of Potential Difference} = M^1 L^2 T^{-3} A^{-1} \]
- **Electric Potential**: Also defined as work done per unit charge.
\[ \text{Dimension of Electric Potential} = M^1 L^2 T^{-3} A^{-1} \]
- **Conclusion**: All three have the same dimensions.

4. **Analyze Set 3: Heat, Work, Energy**:
- **Heat**: A form of energy.
- **Work**: Defined as force times distance, which has the same dimension as energy.
\[ \text{Dimension of Work} = M^1 L^2 T^{-2} \]
- **Energy**: Also has the same dimension as work.
- **Conclusion**: All three have the same dimensions.

5. **Analyze Set 4: Dipole Moment, Electric Flux, Electric Field**:
- **Dipole Moment**: Defined as charge times distance.
\[ \text{Dimension of Dipole Moment} = [Q][L] = A T \cdot L = A^1 L^1 T^1 \]
- **Electric Flux**: Defined as electric field times area.
\[ \text{Dimension of Electric Flux} = [E][A] = \left(\frac{M^1 L^1 T^{-2}}{A T}\right) \cdot L^2 = M^1 L^3 T^{-3} A^{-1} \]
- **Electric Field**: Defined as force per unit charge.
\[ \text{Dimension of Electric Field} = \frac{[F]}{[Q]} = \frac{M^1 L^1 T^{-2}}{A T} = M^1 L^1 T^{-3} A^{-1} \]
- **Conclusion**: The dimensions of dipole moment, electric flux, and electric field are different.

6. **Final Conclusion**:
- The only set that has different dimensions is Set 4: Dipole Moment, Electric Flux, and Electric Field.

### Answer:
The correct option is **Set 4**: Dipole Moment, Electric Flux, Electric Field.