Q. No.
If alpha, beta and gamma rays carry the same momentum, which has the longest wavelength?
1.
Alpha rays
2.
Beta rays
3.
Gamma rays
4.
None, all have same wavelength
The photoelectric effect is used by a photocell to convert:
| 1. | Change in the frequency of light into a change in electric voltage. |
| 2. | Change in the intensity of illumination into a change in photoelectric current. |
| 3. | Change in the intensity of illumination into a change in the work function of the photocathode. |
| 4. | Change in the frequency of light into a change in the electric current. |
1. \(1.5\times 10^{20}\)
2. \(6\times 10^{18}\)
3. \(62\times 10^{20}\)
4. \(3\times 10^{19}\)
1. \(1.3\) V
2. \(0.5\) V
3. \(2.3\) V
4. \(1.8\) V
| 1. | decrease by \(2\) times |
| 2. | decrease by \(4\) times |
| 3. | increase by \(4\) times |
| 4. | increase by \(2\) times |
| 1. | \(1.00\) | 2. | \(1.02\) |
| 3. | \(1.04\) | 4. | \(0.98\) |
1. \(5\times 10^{15}\)
2. \(5\times 10^{16}\)
3. \(5\times 10^{17}\)
4. \(5\times 10^{14}\)
When photons of energy \(h\nu\) fall on an aluminium plate (of work function \(E_0\)), photoelectrons of maximum kinetic energy \(K\) are ejected.
If the frequency of the radiation is doubled, the maximum kinetic energy of the ejected photoelectrons will be:
1. \(K+ E_0\)
2. \(2K\)
3. \(K\)
4. \(K + h\nu\)
In an experiment of the photoelectric effect, the wavelength of incident radiation is . The wavelength of incident radiation is reduced to rd of initial value and the maximum kinetic energy of photoelectron is observed to be n times the previous value. What will be the threshold wavelength for the metal plate?
| 1. | \(\dfrac{n-1}{n-3} \lambda \) | 2. | \(\dfrac{n}{n-3} \lambda \) |
| 3. | \(\dfrac{n-3}{n-1} \lambda \) | 4. | \(\dfrac{n+1}{n-3} \lambda\) |
1. \(0.25~\mathring{A}\)
2. \(0.5~\mathring{A}\)
3. \(1.5~\mathring{A}\)
4. \(2~\mathring{A}\)
© 2026 GoodEd Technologies Pvt. Ltd.