The hysteresis curve for a material is shown in the figure. Then for the material retentivity, coercivity and saturation magnetization respectively will be

Options

A. 1.5 T, 50 A/m and 1.0 T
B. 1.0 T, 50 A/m and 1.5 T
C. 150 A/m, 1.0 T and 1.5 T
D. 1.5 T, 50 A/m and 1.0 T

Answer

To solve the problem regarding the hysteresis curve for a material and to determine the retentivity, coercivity, and saturation magnetization, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Hysteresis Curve**:
- The hysteresis curve is a plot of magnetization (I) versus magnetic intensity (H). It shows how the magnetization of a material responds to an external magnetic field.

2. **Identifying Retentivity**:
- Retentivity is defined as the magnetization that remains in the material when the external magnetic field (H) is reduced to zero.
- From the hysteresis curve, locate the point where H = 0. The corresponding value of I at this point represents the retentivity.
- In the given figure, if the value of I at H = 0 is 1, then the retentivity is **1**.

3. **Identifying Coercivity**:
- Coercivity is the measure of the resistance of a ferromagnetic material to becoming demagnetized. It is defined as the amount of magnetic intensity required to reduce the magnetization to zero after the material has been magnetized.
- From the hysteresis curve, find the value of H at which I returns to 0 after reaching the maximum magnetization. If this value is -50, then the coercivity is **50**.

4. **Identifying Saturation Magnetization**:
- Saturation magnetization is the maximum magnetization that a material can achieve when subjected to a sufficiently strong magnetic field.
- On the hysteresis curve, this is the maximum value of I before it levels off and does not increase with further increases in H. If this value is 1.5, then the saturation magnetization is **1.5**.

5. **Final Values**:
- Based on the observations from the hysteresis curve:
- Retentivity = 1
- Coercivity = 50
- Saturation Magnetization = 1.5

6. **Conclusion**:
- Therefore, the values for retentivity, coercivity, and saturation magnetization are **1, 50, and 1.5**, respectively. The correct option from the provided choices is option number 2.