Home
Class 12
PHYSICS
According to Einstein's theory of relati...

According to Einstein's theory of relativity, mass can be converted into energy and vice-versa. The lightest elementary partical, taken to be the electron, has a mass equivalent to `0.51 MeV` of energ. Then, we can say that

A

the minimum amount of energy avalible through conversition of mass into energy is `1.2 MeV`

B

the least energy of a `lambda`ray photon that can be converted into mass is `1.02 MeV`

C

whereas the minimum energy released by conversion of mass into energy is `1.02 MeV`, it is only a `lambda`- ray photon of energy `0.51 MeV` and above that can be converted into mass

D

whereas the minimum energy released by conversion of mass into energy is `0.51 MeV`, it is only a `lambda`- ray photon of energy `1.01 MeV` and above that can be converted into mass

Text Solution

Verified by Experts

The correct Answer is:
A, B
The correct choices are (a) and (b). The last two statements are incorrect because they violate the principal of conservation of charge. We always have either an electron- positron 'pair production` or an electron- positron 'pairannihilation`. It is only then that the total charge remains zero both before and after reaction.
Promotional Banner

Topper's Solved these Questions

  • ATOMIC PHYSICS

    CENGAGE PHYSICS ENGLISH|Exercise Linked Comprehension|62 Videos

  • ATOMIC PHYSICS

    CENGAGE PHYSICS ENGLISH|Exercise Integer|4 Videos

  • ATOMIC PHYSICS

    CENGAGE PHYSICS ENGLISH|Exercise Single Correct|187 Videos

  • ALTERNATING CURRENT

    CENGAGE PHYSICS ENGLISH|Exercise Single Correct|10 Videos

  • CAPACITOR AND CAPACITANCE

    CENGAGE PHYSICS ENGLISH|Exercise Integer|5 Videos

Similar Questions

Explore conceptually related problems

Theory of relativity reveals that mass can be converted into energy. The energy E so obtained is proportional to certain powers of mass m and the speed c of light. Guess a relation among the quantities using the method of dimensions.

Assertion : In a nuclear process mass gets converted into energy. Reason : According to Einstein's mass energy equivalence relation, mass m is equivalent to energy E, given by the relation E = mc^(2) where c is the speed of light in vacuum.

An electron has a total energy of 2 MeV. Calculate the effective mass of the electron in kg and its speed. Assume rest mass of electron 0.511 MeV.

Einstein's mass - energy relation emerging out of his famous theory of relativity relates mass (m) to energy (E ) as E = mc^2, where c is speed of light in vacuum. At the nuclear level, the magnitudes of energy are vary small. The energy at nuclear level is usually measured in MeV, where 1 MeV = 1.6 xx 10^(-13) J , the masses are measured in unified mass unit (u) where 1 u = 1.67xx10^(-27)kg. (a) Show that the energy equivalent of 1u is 931.5 MeV. (b) A student writes the relation as 1 u = 931.5 MeV. The teacher points out that the relation is dimensionally incorrect. Write the correct relation.

Einstein in 1905 proppunded the special theory of relativity and in 1915 proposed the general theory of relativity. The special theory deals with inertial frames of reference. The general theory of relativity deals with problems in which one frame of reference. He assumed that fixed frame is accelerated w.r.t. another frame of reference of reference cannot be located. Postulated of special theory of realtivity ● The laws of physics have the same form in all inertial systems. ● The velocity light in empty space is a unicersal constant the same for all observers. ● Einstein proved the following facts based on his theory of special relativity. Let v be the velocity of the speceship w.r.t a given frame of reference. The obserations are made by an observer in that reference frame. ● All clocks on the spaceship wil go slow by a factor sqrt(1-v^(2)//c^(2)) ● All objects on the spaceship will have contracted in length by a factor sqrt(1-v^(2)//c^(2)) ● The mass of the spaceship increases by a factor sqrt(1-v^(2)//c^(2)) ● Mass and energy are interconvertable E = mc^(2) The speed of a meterial object can never exceed the velocity of light. ● If two objects A and B are moving with velocity u and v w.r.t each other along the x -axis, the relative velocity of A w.r.t. B = (u-v)/(1-uv//v^(2)) A stationary body explodes into two fragments each of rest mass 1 kg that move apart at speed of 0.6c relative to the original body. The rest mass of the original body is -

Einstein in 1905 proppunded the special theory of relativity and in 1915 proposed the general theory of relativity. The special theory deals with inertial frames of reference. The general theory of relativity deals with problems in which one frame of reference. He assumed that fixed frame is accelerated w.r.t. another frame of reference of reference cannot be located. Postulated of special theory of realtivity ● The laws of physics have the same form in all inertial systems. ● The velocity light in empty space is a unicersal constant the same for all observers. ● Einstein proved the following facts based on his theory of special relativity. Let v be the velocity of the speceship w.r.t a given frame of reference. The obserations are made by an observer in that reference frame. ● All clocks on the spaceship wil go slow by a factor sqrt(1-v^(2)//c^(2)) ● All objects on the spaceship will have contracted in length by a factor sqrt(1-v^(2)//c^(2)) ● The mass of the spaceship increases by a factor sqrt(1-v^(2)//c^(2)) ● Mass and energy are interconvertable E = mc^(2) The speed of a meterial object can never exceed the velocity of light. ● If two objects A and B are moving with velocity u and v w.r.t each other along the x -axis, the relative velocity of A w.r.t. B = (u-v)/(1-uv//v^(2)) The momentum of an electron moving with a speed 0.6 c (Rest mass of electron is 9.1 xx 10^(-31 kg )

Einstein in 1905 proppunded the special theory of relativity and in 1915 proposed the general theory of relativity. The special theory deals with inertial frames of reference. The general theory of relativity deals with problems in which one frame of reference. He assumed that fixed frame is accelerated w.r.t. another frame of reference of reference cannot be located. Postulated of special theory of realtivity ● The laws of physics have the same form in all inertial systems. ● The velocity light in empty space is a unicersal constant the same for all observers. ● Einstein proved the following facts based on his theory of special relativity. Let v be the velocity of the speceship w.r.t a given frame of reference. The obserations are made by an observer in that reference frame. ● All clocks on the spaceship wil go slow by a factor sqrt(1-v^(2)//c^(2)) ● All objects on the spaceship will have contracted in length by a factor sqrt(1-v^(2)//c^(2)) ● The mass of the spaceship increases by a factor sqrt(1-v^(2)//c^(2)) ● Mass and energy are interconvertable E = mc^(2) The speed of a meterial object can never exceed the velocity of light. ● If two objects A and B are moving with velocity u and v w.r.t each other along the x -axis, the relative velocity of A w.r.t. B = (u-v)/(1-uv//v^(2)) One cosmic ray particle appraches the earth along its axis with a velocity of 0.9c towards the north the and another one with a velocity of 0.5c towards the south pole. The relative speed of approcach of one particle w.r.t. another is-