In Young's double-slit experiment, if there is no initial phase difference between the light from the two slits, a point on the screen corresponding to the fifth minimum has a path difference:
1. \( \dfrac{5\lambda}{2} \)
2. \( \dfrac{10\lambda}{2} \)
3. \( \dfrac{9\lambda}{2} \)
4. \( \dfrac{11\lambda}{2} \)
Two polaroids \(P_1\) and \(P_2\) are placed with their axis perpendicular to each other. Unpolarised light of intensity \(I_0\) is incident on \(P_1\). A third polaroid \(P_3\) is kept in between \(P_1\) and \(P_2\) such that its axis makes an angle \(45^\circ\) with that of \(P_1\). The intensity of transmitted light through \(P_2\) is:
1. \(\frac{I_0}{4}\)
2. \(\frac{I_0}{8}\)
3. \(\frac{I_0}{16}\)
4. \(\frac{I_0}{2}\)
For light diverging from a point source:
(a) | the wavefront is spherical. |
(b) | the intensity decreases in proportion to the distance squared. |
(c) | the wavefront is parabolic. |
(d) | the intensity at the wavefront does not depend on the distance. |
1. | (a), (b) | 2. | (a), (c) |
3. | (b), (c) | 4. | (c), (d) |
Two slits are made one millimetre apart and the screen is placed one meter away. What is the fringe separation when blue-green light of wavelength \(500\) nm is used?
1. \(0.5\) mm
2. \(0.3\) mm
3. \(0.05\) mm
4. \(0.03\) mm
Two slits are made one millimetre apart and the screen is placed one metre away. What should the width of each slit be to obtain \(10\) maxima of the double-slit pattern within the central maximum of the single-slit pattern?
1. \(2~\text{mm}\)
2. \(0.2~\text{mm}\)
3. \(0.02~\text{mm}\)
4. \(20~\text{mm}\)
Light is:
1. | a wave phenomenon |
2. | a particle phenomenon |
3. | both particle and wave phenomenon |
4. | none of the above |
Which of the following properties show that light is a transverse wave?
1. reflection
2. interference
3. diffraction
4. polarization
1. | its wavelength and frequency both increase. |
2. | its wavelength increases but frequency remains unchanged. |
3. | its wavelength decreases but frequency remains unchanged. |
4. | its wavelength and frequency both decrease. |
Which of the following sources gives the best monochromatic light?
1. a candle
2. a bulb
3. a mercury tube
4. a laser