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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 megnetic forces do not work on eaxh particle.

C

the magnetic forces do equal and oppite (but non-zero) work on each particle

D

the magnetic forces are necessarily negligible.

Text Solution

Verified by Experts

The correct Answer is:
B
As the magnetic forces due to motion of electron and proton act in a direction perpendicular to the direction of motion , no work is done by these forces. That is why one ignores the magnetic force of one particle on another.
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Knowledge Check

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    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.
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    B
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