MCQ
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : When a charged particle moves perpendicular to magnetic field then its kinetic energy and momentum gets affected.
Reason : Force does not change velocity of charged particle.
  • A
    Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
  • B
    Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
  • C
    $A$ is true, but $R$ is false.
  • $A$ is false, but $R$ is true.

Answer

Correct option: D.
$A$ is false, but $R$ is true.
When a charged particle moves perpendicular to magnetic field, it experiences a force which changes the direction of motion of the particle without changing the magnitude of velocity of the particle. Hence, kinetic energy remains constant but momentum of electron changes.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : The chemical name of bleaching powder is calcium oxychloride.
Reason : Bleaching powder is used as an oxidising agent in chemical industries.
Directions : In the following questions, the Assertions $(A)$ and Reason $(s)\ (R)$ have been put forward. Read both the statements carefully and choose the correct alternative from the following:
Assertion : It is the brain, not the sense organs, that interprets the stimulus.
Reason : Sense organs are transducers; they transform the energy of a stimulus to the energy of nerve impulses.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : $\text{DDT}$ can pass along food chain from crops to man or other animals and harm them.
Reason : $\text{DDT}$ is non $-$ biodegradable and cannot be metabolized within bodies of living organisms and accumulates in their bodies.
For two statements are given-one labelled
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Electron has a negative charge.
Reason: Electrons move always from a region of higher potential to a region of lower potential.
Assertion (A): Ozone is very important layer of atmosphere.
Reason (R): Ozone protects the living organisms from harmful UV radiation of sun.
For question two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below : Assertion : Carbon possesses property of catenation.
Reason : Carbon atoms form double as well as triple bonds during catenation.
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below:
Assertion : Iron is the most widely used metal. But it is never used in its pure state.
Reason : Pure iron is very soft and stretches easily when hot.
For two statements are given- one labelled
Assertion $(A)$ and the other labelled
Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: When pea plants $($pure line$)$ having round yellow seeds are crossed with pure line plants having wrinkled green seeds, then all pea plants obtained in $F_1$ generation bear wrinkled green seeds.
Reason: Round and yellow seeds are dominant to wrinkled and green seeds.
For two statements are given-one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion: Magnesium wire bums in presence of $O_2.$
Reason: Magnesium acts as a reducing agent.
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R)$. Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : Magnetic field interacts with a moving charge and not with a stationary charge.
Reason : A moving charge produces a magnetic field.