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A radiowave is incident on a layer of ionosphere at an angle of 30 degree with the vertical common. If the critical frequency is 1.2 MHz the maximum usable frequency is—
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- 1.2 MHz
- 2.4 MHz
- 0.6 MHz
- 1.386 MHz
Correct Option: D
Relation between maximum usable frequency and critical frequency with incident angle is given by as follows
fmuf = fc sec i
| ∴ fmuf = 1.2 × | × 106 | |
| √3 |
= 1.3856 × 106
= 1.385 MHz
