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When light falls on the cap of the electroscope some electrons are dislodged from the surface leaving a net positive charge on the electroscope. Hence the rod and leaf repel and leaf rises
johnmulu answered the question on February 21, 2017 at 13:13
- A photo of ultraviolet light having energy E falls on a photo emissive surface whose work function is T. Write an expression for maximum kinetic energy of the resulting photoelectron in terms of E and T. (Solved)
A photo of ultraviolet light having energy E falls on a photo emissive surface whose work function is T. Write an expression for maximum kinetic energy of the resulting photoelectron in terms of E and T.
Date posted: February 21, 2017. Answers (1)
- Light of frequency 7.5 x 1014Hz strikes a metal surface whose work function is 4.0 x 10-19 J. Determine the kinetic energy of the emitted photoelectrons. (Solved)
Light of frequency 7.5 x 1014Hz strikes a metal surface whose work function is 4.0 x 10-19 J. Determine the kinetic energy of the emitted photoelectrons. (take planks constant h = 6.63 x 10-34Js)
Date posted: February 21, 2017. Answers (1)
- Define the term "threshold frequency" as used in photo electric emission.(Solved)
State the meaning of the term "threshold frequency" as used in photo electric emission.
Date posted: February 21, 2017. Answers (1)
- What is meant by stopping potential?(Solved)
What is meant by stopping potential?
Date posted: February 21, 2017. Answers (1)
- State the property of radiation that determines the number of electrons emitted when a radiation falls on a metal surface. (Solved)
State the property of radiation that determines the number of electrons emitted when a radiation falls on a metal surface.
Date posted: February 21, 2017. Answers (1)
- If the frequency of the illuminating radiation is just equal to the threshold frequency of the surface explain why no photoelectric effect is observed . (Solved)
If the frequency of the illuminating radiation is just equal to the threshold frequency of the surface explain why no photoelectric effect is observed .
Date posted: February 21, 2017. Answers (1)
- What is meant by the term work function? (Solved)
What is meant by the term work function?
Date posted: February 21, 2017. Answers (1)
- Explain how an "excited" hydrogen atom is able to emit radiations of different wavelengths(Solved)
Explain how an "excited" hydrogen atom is able to emit radiations of different wavelengths
Date posted: February 21, 2017. Answers (1)
- What is photoelectric effect?(Solved)
What is photoelectric effect?
Date posted: February 21, 2017. Answers (1)
- The work function of a certain material is 3.2 eV. Determine the threshold frequency for the material. (1 electron Volt(eV) = 1.6 x 10-19 J and planks Constant h = 6.62 x 10-34Js)(Solved)
The work function of a certain material is 3.2 eV. Determine the threshold frequency for the material. (1 electron Volt(eV) = 1.6 x 10-19 J and planks Constant h = 6.62 x 10-34Js)
Date posted: February 21, 2017. Answers (1)
- The minimum frequency of radiation necessary to cause photoelectric effect on a certain metal surface in 9.06 x 1014Hz. Determine the work function of the metal.(Solved)
The minimum frequency of radiation necessary to cause photoelectric effect on a certain metal surface in 9.06 x 1014Hz. Determine the work function of the metal. (Plank constant h = 6.63 x 10-19Js)
Date posted: February 21, 2017. Answers (1)
- Light of a certain wavelength strikes the surface of a metal. State what determines the maximum kinetic energy of the electron emmitted. (Solved)
Light of a certain wavelength strikes the surface of a metal. State what determines the maximum kinetic energy of the electron emmitted.
Date posted: February 20, 2017. Answers (1)
- It is observed that when ultraviolet light is shone onto a clean zinc plate connected to the cap of negatively charged leaf electroscope, the leaf collapses(Solved)
It is observed that when ultraviolet light is shone onto a clean zinc plate connected to the cap of negatively charged leaf electroscope, the leaf collapses. Explain this observation
Date posted: February 20, 2017. Answers (1)
- The anode of an x-ray tube becomes hot when the tube is in use. State the reason for this.(Solved)
The anode of an x-ray tube becomes hot when the tube is in use. State the reason for this.
Date posted: February 20, 2017. Answers (1)
- An x-ray tube produces soft x-rays. State the adjustment that may be made so that the tube produces hard x-rays(Solved)
An x-ray tube produces soft x-rays. State the adjustment that may be made so that the tube produces hard x-rays
Date posted: February 20, 2017. Answers (1)
- An x-ray tube produces soft x-rays. State the adjustment that may be made so that the tube produces hard x-rays.(Solved)
An x-ray tube produces soft x-rays. State the adjustment that may be made so that the tube produces hard x-rays.
Date posted: February 20, 2017. Answers (1)
- In an X-ray tube it is observed that the intensity of X-rays increases when potential difference across the filament is increased.(Solved)
In an X-ray tube it is observed that the intensity of X-rays increases when potential difference across the filament is increased. Explain this observation
Date posted: February 20, 2017. Answers (1)
- The accelerating potential of a certain X-ray tube is increased. State the change observed on the X-rays produced.(Solved)
The accelerating potential of a certain X-ray tube is increased. State the change observed on the X-rays produced.
Date posted: February 20, 2017. Answers (1)
- State the reason and the effect on the X-rays produced in an X-ray tube, when the p.d across the tube is increased. (Solved)
State the reason the effect on the X-rays produced in an X-ray tube, when the p.d across the tube is increased.
Date posted: February 20, 2017. Answers (1)
- The target of X-ray tube is made of metals of high melting point,give reason(Solved)
The target of X-ray tube is made of metals of high melting point. Give a reason for this
Date posted: February 20, 2017. Answers (1)