Refraction by Prism: Practice Problem & Solution
Assertion (A): Consider a prism A of refracting angle \(5^0\), and another prism B of refracting angle \(10^0\), . Both prisms are made of crown glass. If white light is incident on each prism, angular dispersion caused by prism B will be more. Reason (R): Dispersive power depends on the nature material.
Short Solution (Best for NEET):
To solve this problem, we apply the core principles of Refraction by Prism. Understanding the underlying formula is key to arriving at the correct answer below:
Angular dispersion is given by \(\delta = (\mu_v - \mu_r)A\), . Since both prisms are of the same material, \((\mu_v - \mu_r\),), is constant. Prism B has a larger angle (A), \((10^\circ\), vs \(5^\circ\),), so it will cause more angular dispersion, making A true. Dispersive power is indeed a property of the material, so R is true. However, R does not explain why prism B has more dispersion than A, which is due to its larger refracting angle.
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