A travelling microscope is focussed on a mark on a piece of paper and the scale reading is A. A rectangular block of glass is placed on the paper and the microscope is raised and focussed the mark on the paper, then microscope reading is B. A layer of lycopodium powder is sprinkled on the block of glass, the reading now is C. The refractive index of the material of the block is
$\frac{C - B}{C - A}$
$\frac{C}{C - A}$
$\frac{C - A}{B - A}$
$\frac{C - A}{C - B}$

Question

A travelling microscope is focussed on a mark on a piece of paper and the scale reading is A. A rectangular block of glass is placed on the paper and the microscope is raised and focussed the mark on the paper, then microscope reading is B. A layer of lycopodium powder is sprinkled on the block of glass, the reading now is C. The refractive index of the material of the block is
$\frac{C - B}{C - A}$
$\frac{C}{C - A}$
$\frac{C - A}{B - A}$
$\frac{C - A}{C - B}$

Toppr Admin · Accepted Answer

The refractive index of the glass slab will be equal to-x3BC-Real-xA0-DepthApparent-xA0-depthNow- for the given case- Real Depth - C - AApparent depth - C - B-xA0-Thus- -x3BC-C-x2212-AC-x2212-B

The refractive index of the glass slab will be equal to,μ=Real DepthApparent depthNow, for the given case, Real Depth = C - AApparent depth = C - B Thus, μ=C−AC−B

The refractive index of the glass slab will be equal to,

$μ = \frac{R e a l D e p t h}{A p p a r e n t d e p t h}$

Now, for the given case, Real Depth = C - A

Apparent depth = C - B

Thus, $μ = \frac{C - A}{C - B}$