A photo-cell is illuminated by a source of light, which is placed at a distance \(d\) from the cell. If the distance becomes \(\dfrac{d}{2}\), then the number of electrons emitted per second will be:
1. same
2. four times
3. two times
4. one-fourth
1. | work function of material |
2. | intensity of incident radiation |
3. | frequency of incident radiation |
4. | wavelength of incident radiation |
The wavelength of light in the visible region is about \(550\) nm (average wavelength) for yellow-green colour. Three materials with work functions are given as Al (\(4.28\) eV), Cu (\(4.65\) eV) and Na (\(2.75\) eV). From which of these photosensitive materials, can you build a photoelectric device that operates with visible light?
1. Al
2. Cu
3. Na
4. none of the above
1. | \(V_0 /2\) | 2. | \(V_0 \) |
3. | \(4V_0 \) | 4. | \(2V_0 \) |
In a photoelectric experiment, blue light is capable of ejecting a photoelectron from a specific metal while green light is not able to eject a photoelectron. Ejection of photoelectrons is also possible using light of the colour:
1. yellow
2. red
3. violet
4. orange
1. | be tripled. |
2. | be more than tripled. |
3. | be less than tripled. |
4. | become one third. |
1. | \(x\)-axis (frequency) | a straight line with a positive intercept on the
2. | \(y\)-axis (kinetic energy) | a straight line with a positive intercept on the
3. | a parabola |
4. | a hyperbola |