question_answer

A ray of light is incident on the surface of a glass plate of thickness f. If the angle of incidence Q is small, the emerging ray would be displaced side ways by an amount [Take n = refractive index of glass)

A)  \[\Omega \]     

B)        \[\Omega \]     

C)        \[\phi \]             

D)        \[\phi ={{\phi }_{0}}+4t\]

Correct Answer: B

Solution :

In \[\frac{1}{4\lambda }\] \[4\lambda \] \[2\lambda \] or  \[\frac{1}{2\lambda }\]                   ??(i) In \[\frac{qvR}{2}\] \[qv{{R}^{2}}\] or  \[\frac{qv{{R}^{2}}}{2}\]                   ??.(ii) From Eqs. (i) and (ii), we get \[qvR\] \[{{L}_{A}}\] \[{{L}_{B}}\] If n is the refractive index of material of slab (glass) w.r.t. air, then \[{{L}_{A}}>{{L}_{B}}\] For small angle, \[{{L}_{A}}={{L}_{B}}\] or   \[{{L}_{A}}\] and \[{{L}_{B}}\][\[{{L}_{A}}<{{L}_{B}}\] \[\Omega \] and \[\Omega \] if \[\pi \] is small] \[\pi \] or  \[\pi \]