The resolving power of a compound microscope will be maximum when:
1. | red light is used to illuminate the object. |
2. | violet light is used to illuminate the object instead of red light. |
3. | infrared light is used to illuminate the object instead of visible light. |
4. | the microscope is in normal adjustment. |
If the light is polarised by reflection, then the angle between reflected and refracted light is:
1. | \(\pi\) | 2. | \(\dfrac{\pi}{2}\) |
3. | \(2\pi\) | 4. | \(\dfrac{\pi}{4}\) |
Two sources with intensity \(I_0\) and \(4I_0\) respectively interfere at a point in a medium. The maximum and the minimum possible intensity respectively would be:
1. \(2I_0, I_0\)
2. \(9I_0, 2I_0\)
3. \(4I_0, I_0\)
4. \(9I_0, I_0\)
The relation between the fringe width for the red light and yellow light is: (all other things being the same.)
1. \(\beta_\text{red} < \beta_\text{yellow}\)
2. \(\beta_\text{red} > \beta_\text{yellow}\)
3. \(\beta_\text{red} = \beta_\text{yellow}\)
4. \(\beta_\text{red} =2 \beta_\text{yellow}\)
Fringe width in a particular Young's double-slit experiment is measured to be \(\beta.\) What will be the fringe width if the wavelength of the light is doubled, the separation between the slits is halved and the separation between the screen and slits is tripled?
1. \(10\) times
2. \(11\) times
3. Same
4. \(12\) times
In Young's double-slit experiment, the slits are separated by \(0.28\) mm and the screen is placed \(1.4\) m away. The distance between the first dark fringe and the fourth bright fringe is obtained to be \(0.6\) cm. The wavelength of the light used in the experiment is:
1. \(3.4 \times 10^{-7}~\text{m}\)
2. \(4.1 \times 10^{-7}~\text{m}\)
3. \(3.4 \times 10^{-9}~\text{m}\)
4. \(4.1 \times 10^{-9}~\text{m}\)
Light of wavelength \(6328~\mathring{A}\) is incident normally on a slit having a width of \(0.2\) mm. The width of the central maximum measured from minimum to minimum of diffraction pattern on a screen \(9\) m away will be nearly:
1. \(0.36^{\circ}\)
2. \(0.18^{\circ}\)
3. \(0.72^{\circ}\)
4. \(0.09^{\circ}\)
The first diffraction minima due to a single slit diffraction is at \(\theta = 30^{\circ}\) for a light of wavelength \(5000~\mathring {A}.\) The width of the slit is:
1. \(5\times 10^{-5}~\text{cm}\)
2. \(10\times 10^{-5}~\text{cm}\)
3. \(2.5\times 10^{-5}~\text{cm}\)
4. \(1.25\times 10^{-5}~\text{cm}\)
A plane-polarized light with intensity \(I_0\) is incident on a polaroid with an electric field vector making an angle of \(60^{\circ}\) with the transmission axis of the polaroid. The intensity of the resulting light will be:
1. | \(\dfrac{I_0}{4}\) | 2. | \(I_0\) |
3. | \(2I_0\) | 4. | \(\dfrac{I_0}{2}\) |
Which of the following is not true?
1. | The speed of light is dependent on the colour of the light. |
2. | The speed of violet light is less than the speed of the red light in glass. |
3. | The frequency of light never depends upon the property of the medium. |
4. | When the light diverges from a point source, the shape of the wavefront is plane. |