`(i)` Identify the part of electronmagnetic spectrum which is :
`(a)` suitable for radar system used in aircraft navigation,
`(b)` Produced by bombarding a metal target by high speed electrons.

Explanation

To solve the question, we need to identify specific parts of the electromagnetic spectrum based on the given criteria.

### Step-by-Step Solution:

1. **Identify the part of the electromagnetic spectrum suitable for radar systems used in aircraft navigation:**
- Radar systems typically operate using electromagnetic waves that can penetrate the atmosphere and provide accurate distance measurements.
- The part of the electromagnetic spectrum that is most suitable for radar systems is the **microwave** region. Microwaves have wavelengths ranging from about 1 mm to 1 m and are effective for radar applications due to their ability to reflect off objects and provide information about their distance and speed.

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