Home
Class 11
PHYSICS
An electron and a proton are moving unde...

An electron and a proton are moving under the influence of mutual forces. In calculating the change in the kinetic energy of the system during motion, one ignores the magnetic force of one on another. This is because,

A

the two magnetic forces are equal and opposite, so they produce no net effect

B

the magnetic forces do not work on each particle

C

the magnetic forces do equal and opposite (butnon-zero) work on each particle

D

the magnetic forces are necessarily negligible

Text Solution

Verified by Experts

The correct Answer is:
B
(b) When electron and proton are moving under influence of their mutual forces, the magnetic forces will be perpendicular to their motion hence no work is doneby these forces.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • WORK, ENERGY AND POWER

    DC PANDEY|Exercise MEDICAL ENTRANCE SPECIAL QUESTIONS|16 Videos

  • WORK, ENERGY AND POWER

    DC PANDEY|Exercise MATCH THE COLUMNS|7 Videos

  • WORK, ENERGY AND POWER

    DC PANDEY|Exercise CHECK POINT 6.3|10 Videos

  • WORK, ENERGY & POWER

    DC PANDEY|Exercise Level 2 Comprehension Based|2 Videos

  • WORK, POWER AND ENERGY

    DC PANDEY|Exercise E Integer Type Questions|11 Videos

Similar Questions

Explore conceptually related problems

There is no change in the energy of a charged particle moving in a magnetic field although a magnetic force is acting on it .

An electron and proton have the same de-broglie wavelength. Which one of these has higher kinetic energy? Which one is moving faster?

Knowledge Check

  • Assertion: Internal forces cannot change linear momentum. Reason: Internal forces can change the kinetic energy of a system.

    A
    (a) If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
    B
    (b) If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
    C
    (c) If Assertion is true, but the Reason is false.
    D
    (d) If Assertion is false but the Reason is true.

  • A : Internal forces can change the kinetic energy but not the momentum of the system. R : The net internal force on a system is always zero.

    A
    If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
    B
    If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
    C
    If Assertion is true statement but Reason is false, then mark (3).
    D
    If both Assertion and Reason are falsė statements, then mark (4).

  • A particle is moving under the influence of a force which is fixed in magnitude and acting at an angle theta in the direction of motion. The path described by the particle is

    A
    a circle
    B
    an ellipse
    C
    a parabola
    D
    a straight line

    • Similar Questions

    Explore conceptually related problems

    An electron is either released from rest or projected with some initial velocity in a uniform electric field. Neglect any other force on the electron apart from electrostatic force. Which of the graphs shown in fig could possibly represent the change in kinetic energy of the electron during its course of motion? Explain the situation in each case.

    An electron and a proton are moving with the same kinetic energy along the same direction, When they pass through a uniform magnetic field perpendicular to the direction of their motion, they describe circular path of the same radius. Is this statement true or false?

    An electron and a proton are moving with the same kinetic energy along the same direction . When they pass through a uniform magnetic field perpendicular to the direction of their motion , they describe circular paths of the same radius.

    Assertion : Internal forces acting on the system cannot change linear momentum of the system . Reason : Internal forces can change kinetic energy of the system.

    Consider the following statements I. The rate of change of the total linear momentum of a system consisting of many particles is proportional to the vector sum of all the internal forces due to inter-particle interaction. The internal forces can change the kinetic energy of the system of particles are not the linear momentum of the system. Choose the correct option.

    Home
    Profile