List-I (Sol) | List-II (Method of preparation) |
---|---|
A) \( \text{As}_2\text{S}_3 \) | I) Bredig's arc method |
B) \( \text{Au} \) | II) Oxidation |
C) \( \text{S} \) | III) Hydrolysis |
D) \( \text{Fe(OH)}_3 \) | IV) Double decomposition |
Explain the construction of a spherical wavefront by using Huygens' principle.
The slope of the tangent to the curve \( x = \sin\theta \) and \( y = \cos 2\theta \) at \( \theta = \frac{\pi}{6} \) is ___________.