A beaker containing liquid is placed on a table, underneath a mic… - Vidyadip

MCQ

A beaker containing liquid is placed on a table, underneath a microscope which can be moved along a vertical scale. The microscope is focussed, through the liquid onto a mark on the table when the reading on the scale is $a$. It is next focussed on the upper surface of the liquid and the reading is $b.$ More liquid is added and the observations are repeated, the corresponding readings are $c$ and $d.$ The refractive index of the liquid is

✓
$\frac{{d - b}}{{d - c - b + a}}$
B
$\frac{{b - d}}{{d - c - b + a}}$
C
$\frac{{d - c - b + a}}{{d - b}}$
D
$\frac{{d - b}}{{a + b - c - d}}$

✓

Answer

Correct option: A.

$\frac{{d - b}}{{d - c - b + a}}$

a
(a) The real depth $ = \mu $ ( apparent depth)

$ \Rightarrow $ In first case, the real depth ${h_1} = \mu (b - a)$

Similarly in the second case, the real depth ${h_2} = \mu (d - c)$

Since ${h_2} > {h_1},$ the difference of real depths

$ = {h_2} - {h_1} = \mu (d - c - b + a)$

Since the liquid is added in second case,

${h_2} - {h_1} = (d - b)$ $ \Rightarrow \,\,\mu = \frac{{(d - b)}}{{(d - c - b + a)}}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 9. Ray optics abd optical instruments→9. Ray optics abd optical instruments — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

The combined capacity of the parallel combination of two capacitors is four times their combined capacity when connected in series. This means that

Assertion : Television signals are received through sky-wave propagation.
Reason : The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency.

A circular loop of wire is in the same plane as an infinitely long wire carrying a constant current $i$. Four possible motions of the loop are marked by $N, E$, $W$, and $S$ as shown below. A clockwise current is induced in the loop when loop is pulled towards

A dimensionless quantity:

When the electron in the hydrogen atom jumps from $2^{nd}$ orbit to $1^{st}$ orbit, the wavelength of radiation emitted is $\lambda$. When the electrons jump from $3^{rd}$ orbit to $1^{st}$ orbit, the wavelength of emitted radiation would be

If the inductance and capacitance are both doubled in $\text{L - C - R}$ circuit, the resonant frequency of the circuit will:

Light is incident normally on a completely absorbing surface with an energy flux of $25\,W\,cm^{-2}.$ If the surface has an area of $25\,cm^2,$ the maximum momentum transferred to the surface in $40\,min$ time duration will be

If a diamagnetic substance is brought near north or south pole of a bar magnet, it is

Shown in the figure is a circular loop of radius r and resistance R. A variable magnetic field of induction $B=B_0 e^{-t}$ is established inside the coil. If the key (K) is closed, the electrical power developed right after closing the switch is equal to

Two metallic plates form a parallel plate capacitor. The distance between the plates is $'d'.$ A metal sheet of thickness $\frac{d}{2}$ and of area equal to area of each plate is introduced between the plates. What will be the ratio of the new capacitance to the original capacitance of the capacitor $?$