Download App

Light Waves — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsLight Waves1 Mark
Question
Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio:
  1. 25 : 1
  2. 5 : 1
  3. 9 : 4
  4. 625 : 1
✓

Answer

  1. 9 : 4

Explanation:

Ratio of maximum intensity and minimum intensity is given by

$\frac{\text{I}_\text{max}}{\text{I}_\text{min}}=\frac{(\sqrt{\text{I}_1}+\sqrt{\text{I}_2})^2}{(\sqrt{\text{I}_1}-\sqrt{\text{I}_2})^2}=\frac{25}{1}$

$\Rightarrow\sqrt{\text{I}_1}=3 \ \text{and}\ \sqrt{\text{I}_2}=2$

$\Rightarrow\text{I}_1=9\ \text{and}\ \text{I}_2=4$

Then,

$\frac{\text{I}_1}{\text{I}_2}=\frac{9}{4}$

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 [1M]" from Light Waves→Light Waves — all question types→Physics STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

Two unlike charges of magnitude q are separated by a distance 2d. The potential at a point midway between them is

(a) Zero

(b)  

(c)

(d)

→
Which of the following parameters are the same for all hydrogen-like atoms and ions in their ground states?
  1. Radius of the orbit.
  2. Speed of the electron.
  3. Energy of the atom.
  4. Orbital angular momentum of the electron.
→

The Young's experiment is performed with the lights of blue (λ = 4360 Å) and green colour (λ = 5460 Å), If the distance of the 4th fringe from the centre is x, then

(a) x (Blue) = x (Green)

(b) x (Blue) > x (Green)

(c) x (Blue) < x (Green)

(d)

→
In figure, there is a conducting ring having resistance R placed in the plane of paper in a uniform magnetic field B0​. If the ring is rotating in the plane of paper about an axis passing through point O and perpendicular to the plane of paper with constant angular speed $\omega$ in clockwise direction, then.
Image
→
The wavelength of a photon needed to remove a proton from a nucleus which is bound to the nucleus with 1MeV energy is nearly:
→
Wavelength of which series in hydrogen spectrum lies in visible region ?
→

The focal lengths of convex lens for red and blue light are 100 cm and 96.8 cm respectively. The dispersive power of material of lens is

(a) 0.325

(b) 0.0325

(c) 0.98   

(d) 0.968
→

In a biprism experiment, by using light of wavelength 5000 Å, 5 mm wide fringes are obtained on a screen 1.0 m away from the coherent sources. The separation between the two coherent sources is

(a) 1.0 mm

(b) 0.1 mm

(c) 0.05 mm

(d) 0.01 mm
→

When a body is earth connected, electrons from the earth flow into the body. This means the body is….

(a) Unchanged

(b) Charged positively

(c) Charged negatively

(d) An insulator
→

By properly combining two prisms made of different materials, it is possible to:

→