Question
State one feature by which the phenomenon of interference can be distinguished from that of diffraction.
A parallel beam of light of wavelength 600 nm is incident normally on a slit of width ‘a’. If the distance between the slit and the screen is 0.8 m and the distance of 2nd order maximum from the centre of the screen is 15 mm, calculate the width of the slit.

Answer

The given features:-
Interference Diffraction
  1. Fringes of equal width
Fringes of unequal width
  1. Fringes of equal intensity
Fringes of decreasing intensity
  1. Due to superposition of two waves (wavefronts)
Due to superposition of secondary wavefronts.
  1. Maximal at $\theta =\frac{\lambda}{\text{a}}$
Minima at $\theta = \frac{\lambda}{\text{a}}$
$\text{ (Numerical : Formula}\text{ y} =\frac{(2\text{n} + 1)\lambda\text{D}}{2\text{a}}\text{ or } \frac{5\lambda\text{D}}{2\text{a}}$
Substitution and Result: $8 × 10^{-5}\ m$ or $0.08\ mm.$

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

Similar questions

A bulb is made using two filaments. A switch selects whether the filaments are used individually or in parallel. When used with a 15V battery, the bulb can be operated at 5W, 10W or 15W. What should be the resistances of the filaments?
Why is the orientation of the portable radio with respect to broadcasting station important?
Free electron density of copper is $8.5 \times 10^{28}$ per $m ^3$. Find out the current in copper wire of length 0.1 m and area of cross-section $1 mm^2$ when a battery of 3 V is joined across its ends. (Given mobility of electrons = $4.5 \times 10^{-6} m^2 V^{-1} s^{-1}$, charge on electron, $e=1.6 \times 10^{-19} C$ )
An electron gun emits $2.0 × 10^{16}$ electrons per second. What electric current does this correspond to?
Consider the situation of the previous problem. Take "the table plus the ball" as the system. Friction between the table and the ball is then an internal force. As the ball slows down, the momentum of the system decreases. Which external force is responsible for this change in the momentum?
What physical quantity is the same for Χ-rays of wavelength $10^{-10}m,$ red light of wavelength $6800\mathring{\text{A}}$ and radio waves of wavelength 500m?
The magnetic field inside a tightly wound, long solenoid is $\text{B}=\mu_0\text{ni}.$ It suggests that the field does not depend on the total length of the solenoid, and hence if we add more loops at the ends of a solenoid the field should not increase. Explain qualitatively why the extra-added loops do not have a considerable effect on the field inside the solenoid.
Write Kirchhoff's junction rule. Write the magnitude of current $I$ in the given figure.
Image
What is paramagnetic substance?
Write the function of a (i) Transducer and (ii) Repeater in a communication system.