Mixture of Colours

Q. In Youngs double slit experiment, if the two slits are illuminated with separate sources, no interference pattern is observed because

1. there will be no constant phase difference between the two waves
2. the wavelengths are not equal
3. none of the above
4. the amplitudes are not equal

Q.

The Youngs experiment is performed with lights of blue ($\lambda =4360\AA$) and green colour ($\lambda =5460\AA$). If the distance of the $4^{th}$ fringe from the centre is $x$, then

1. $x\left(Blue\right)>x\left(Green\right)$

2. $x\left(Blue\right)<x\left(Green\right)$
3. $x\left(Blue\right)=x\left(Green\right)$
4. 
   $\frac{x\left(Blue\right)}{x\left(Green\right)}=\frac{5460}{4360}$

Q.

Light of different colours propagates through air

1. with the velocity of air
2. with different velocities
3. with the velocity of sound
4. having equal velocities

Q.

In Young's double slit experiment, if monochromatic light is replaced by white light

[AIIMS 2001; Kerala PET 2000; KCET 2004]

1. All bright fringes have colours between violet and red

2. Only the central fringe is white, all other fringes are coloured

3. All bright fringes become white

4. No fringes are observed

Q.

By a monochromatic wave, we mean

[AFMC 1995]

1. A single ray

2. A single ray of a single colour

3. Wave having a single wavelength

4. Many rays of a single colour

Q. Double slit experiment performed by Thomas Young showed that light coming from two coherent sources interfere and produce maxima and minima depending on the path difference. This experiment shows that light behaves as-

1. Particle
2. Wave
3. Both
4. None

Q. A Young's double slit experiment is performed with white light.

1. The central fringe will be white.
2. The fringe next to the central fringe will be red.
3. The fringe next to the central fringe will be violet.
4. There won't be a completely dark fringe.

Q. If a torch is used in place of monochromatic light in Young's experiment what will happens?

1. Fringe will appear for a moment then, it will disappear
2. Fringes will occur as from monochromatic light
3. Only bright fringes will appear
4. No fringes will appear

Q. Double slit experiment performed by Thomas Young showed that light coming from two coherent sources interfere and produce maxima and minima depending on the path difference. This experiment shows that light behaves as-

Q. For the sustained interference of light, the necessary condition is that the two sources should:

1. Have constant phase difference
2. Be narrow
3. Be close to each other
4. Of same amplitude

Q. Assertion :In Young's experiment, the fringe width for dark fringes is equal to that for white fringes. Reason: In Young's double slit experiment the fringes are performed with a source of white light, then only black and bright fringes are observed.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

In Young's double slit experiment, if monochromatic light is replaced by white light

[AIIMS 2001; Kerala PET 2000; KCET 2004]

1. All bright fringes become white

2. All bright fringes have colours between violet and red

3. Only the central fringe is white, all other fringes are coloured

4. No fringes are observed

Q.

if white light is used in youngs double slit experiment, what is the colour of the bright fringe closest on either side of the central fringe?

Q.

Why are coherent sources required to produce the interference of light?

Q.

By a monochromatic wave, we mean

[AFMC 1995]

1. A single ray

2. Wave having a single wavelength

3. A single ray of a single colour

4. Many rays of a single colour

Q.

In Young's double slit experiment, if monochromatic light is replaced by white light

[AIIMS 2001; Kerala PET 2000; KCET 2004]

1. All bright fringes become white

2. All bright fringes have colours between violet and red

3. Only the central fringe is white, all other fringes are coloured

4. No fringes are observed

Q.

In Young's double slit experiment, if the two slits are illuminated with separate sources, no interference pattern is observed because

1. The wavelengths are not equal

2. There will be no constant phase difference between the two waves

3. The amplitudes are not equal

4. None of the above

Q. What is the value of the emissivity of a perfect black body?

Q. What is the effect on the interference fringes in a Young's double slit experiment when (i) the width of the two slits is increased (ii) the monochromatic source is replaced by a source of white light and (iii) the separation between the two slits is increased, keeping other variables constant in each case?

Q.

In Young's double slit experiment, if monochromatic light is replaced by white light

[AIIMS 2001; Kerala PET 2000; KCET 2004]

1. All bright fringes become white

2. All bright fringes have colours between violet and red

3. Only the central fringe is white, all other fringes are coloured

4. No fringes are observed

Q. As a result of interference of two coherent sources of light, energy is:

1. increased
2. redistributed and the distribution does not vary with time
3. redistributed and that distribution changes with time
4. decreased

Q.

Q:- WHAT IS MONOCHROMATIC LIGHT IN PHOTOELECTRIC EFFECT WHAT ARE ITS USES?

Q. There are two sets of apparatus of Young?s double slit experiment. In set A, the phase difference between the two waves emanating from the slits does not change with time, whereas in set B, the phase difference between the two waves from the slits changes
rapidly with time. What difference will be observed in the pattern obtained on the screen in the two set ups?

Q. Write true or false for the following statements :
When a beam of white light is passed through a prism , violet color bends the most and red color the least.

1. True
2. False

Q. Why are coherent sources required to produce interference of light?

Q. In Young's interference experiment, if the slits are of unequal width, then

1. no fringes will be formed
2. the positions of minimum intensity will not be completely dark
3. bright fringe as displaced from the original central position
4. distance between two consecutive dark fringes will not be equal to the distance between two consecutive right fringes.

Q. In Young's experiment $\lambda =$ 4000Å fringes observed have a width $\beta$ . The light illuminating with new $\lambda =$ 6000Å and the separation between the interfering sources is halved. The ratio of the distance between the screen and the interfering sources if the fringe width remains unaltered respectively is:

1. 3/1
2. 3/4
3. 1/3
4. 2/3