Advertisements
Advertisements
प्रश्न
State three factors on which the rate of emission of electrons from a metal surface depends
Advertisements
उत्तर १
A rate of emission of electrons from a metal surface depends on
(1) Nature of the metal surface: Lower the work function of the metal, greater is the rate of emission of electrons from its surface.
(2) The temperature of the surface: Higher the temperature of the surface, greater is the rate of emission of electrons from the surface.
(3) Surface area of the metal: Larger the surface area of the metal emitting electrons, greater is the rate of emission of electrons.
उत्तर २
(i) The material of the surface,
(ii) The temperature of the surface,
(iii) The surface area of the surface.
APPEARS IN
संबंधित प्रश्न
A radiation X is focused by a particular device on the bulb of a thermometer and mercury in the thermometer shows a rapid increase. Name the radiation X
Answer the following questions based on a hot cathode ray tube.
State the approximate voltage used to heat the filament
An element `""_ZS^A` decays to `""_85R^222` after emitting 2 α particles and 1 β particle.
Find the atomic number and atomic mass of the element S.
A radioactive source emits three types of radiations. Name them.
(i) Name the radiations which are charged.
(ii) Name the radiations which are most penetrating.
(iii) Name the radiations which travel with the speed of light.
(iv) Name the radiations which have the largest mass.
Draw a diagram of a simple atom showing the nucleus and electrons. In this atom:
(a) What type of charge will there be on the nucleus?
(b) What is the value of this charge?
Explain the use of radioactive in the field of medicine, agriculture and industry.
Define bound electrons.
What are ‘Becquerel rays’?
A certain nucleus has a mass number 20 and atomic number 9. Find the number of neutrons and protons present in it.
State one use of radio-isotopes.
