Download App

Dispersion and Spectra — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsDispersion and Spectra3 Marks
Question
A certain material has refractive indices 1.56, 1.60 and 1.68 for red, yellow and violet light respectively.
  1. Calculate the dispersive power.
  2. Find the angular dispersion produced by a thin prism of angle 6° made of this material.
✓

Answer

Given that,$\mu_\text{r}=1.56,\mu_\text{y}=1.60,\ \text{and}\ \mu_\text{v}=1.68$
  1. Dispersive power $=\omega=\frac{\mu_\text{v}-\mu_\text{r}}{\mu_\text{y}-1}=\frac{1.68-1.56}{1.60-1}$
$=\frac{0.12}{0.60}=0.2$​​​​​​​
  1. Angular dispersion $=(\mu_\text{v}-\mu_\text{r})\text{A}=0.12\times6^\circ=7.2^\circ$

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 "3 Marks Question" from Dispersion and Spectra→Dispersion and Spectra — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Calculate the number of states per cubic metre of sodium in 3s band. The density of sodium is $1013kg/ m^3.$ How many of them are empty?
→
Calculate the binding energy per $^{40}_{20}\text{CA}$ nucleon nucleus.
[Given: m $\big(^{40}_{20}\text{Ca}\big)=39.962589\text{u}$
$m_n($mass od a neutron$) = 1.008665u$
$m_p($mass of a proton$) =1.007825u$
$1u = 931\ MeV/c^2]$
→
Carbon (Z = 6) with mass number 11 decays to boron (Z = 5).
  1. Is it a $\beta^+-\text{decay}$ or a $\beta^--\text{decay}?$
  2. The half-life of the decay scheme is 20.3 minutes. How much time will elapse before a mixture of 90% carbon-11 and 10% boron-11 (by the number of atoms) converts itself into a mixture of 10% carbon-11 and 90% boron-11?
→
It is found that photosynthesis starts in certain plants when exposed to the sunlight but it does not start if the plant is exposed only to infrared light. Explain.
→
A monkey of mass 15kg is climbing on a rope with one end fixed to the ceiling. If it wishes to go up with an acceleration of $1m/s^2,$ how much force should it apply to the rope? If the rope is 5m long and the monkey starts from rest, how much time will it take to reach the ceiling?
→
State briefly the underlying principle of a transistor oscillator. Draw a circuit diagram showing how the feedback is accomplished by inductive coupling. Explain the oscillator action.
→
Suppose A and B in the previous problem change their positions in such a way that the line joining them becomes perpendicular to the direction of wind while maintaining the separation x. What will be the time lag B finds between seeing and hearing the drum beating by A?
→
The work function of a metal is $2.5 \times 10^{-19}\ J.$​​​​​​​
  1. Find the threshold frequency for photoelectric emission.
  2. If the metal is exposed to a light beam of frequency $6.0 \times 10^{-14}\  Hz$, what will be the stopping potential?
→
Estimate the proportion of boron impurity whieh will increase the conductivity of a pure silicon sample by a factor of 100. Assume that each boron atom creates a hole and the concentration of holes in pure silicon at the same temperature is $7 \times 10^{15}$ holes per cubic metre. Density of silicon is $5 \times 10^{21}$ atoms per cubic metre.
→
A block of mass 250g is kept on a vertical spring of spring constant 100N/m fixed from below. The spring is now compressed to have a length 10cm shorter than its natural length and the system is released from this position. How high does the block rise? Take $g =10m/s^2.$
→