You can remove iron filings from sand by magnetic separation method. This method can be applied only when

Options

A. magnetic substances are mixed up with non magnetic substances
B. magnetic substances are mixed up with magnetic substances
C. magnet
D. sieving

Answer

To solve the question about when the magnetic separation method can be applied to remove iron filings from sand, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Magnetic Separation**:
- Magnetic separation is a technique used to separate magnetic materials from non-magnetic materials in a mixture.

2. **Identifying the Components**:
- In this case, we have a mixture of iron filings (which are magnetic) and sand (which is non-magnetic).

3. **Condition for Magnetic Separation**:
- For magnetic separation to be effective, there must be at least one magnetic material and one non-magnetic material in the mixture. This allows the magnet to attract the magnetic material while leaving the non-magnetic material behind.

4. **Application to the Given Mixture**:
- Since iron filings are magnetic and sand is non-magnetic, we can apply the magnetic separation method. The magnet will attract the iron filings, and the sand will remain unaffected.

5. **Conclusion**:
- Therefore, the magnetic separation method can be applied when there are magnetic substances mixed with non-magnetic substances.

### Final Answer:
The magnetic separation method can be applied only when there are magnetic substances mixed with non-magnetic substances.

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