Download App

Nuclei — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsNuclei1 Mark
Question
For question, 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.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is NOT the correct explanation of A.
  3. A is true, but R is false.
  4. A is false and R is also false.
Assertion (A): For the fission of heavy nuclei, neutrons are more effective than protons.
Reason (R): Neutrons are heavier than protons.
✓

Answer

  1. Both A and R are true, but R is NOT the correct explanation of A.
Explanation:
A neutron is slightly heavier than a proton. As neutrons are charge less particles, they penetrate matter more than protons. Therefore, they are more effective than protons in fission reactions.

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

Explore more

More "Assertion (A) & Reason (B) MCQ" from Nuclei→Nuclei — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

Assertion (A): Two adjacent conductors of unequal dimensions, carrying the same positive charge have a potential difference between them.
Reason (R): The potential of a conductor depends upon the charge given to it.
→
Assertion (A): Positive charge always moves from a higher potential point to a lower potential point. 
Reason (R): Electric potential is a vector quantity.
→
Assertion (A): Transformers are used only in alternating current sources, not in direct current.
Reasons (R): Only a.c. can be stepped up or down by means of transformers.
→
For question, 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.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is NOT the correct explanation of A.
  3. A is true, but R is false.
  4. A is false and R is also false.
Assertion (A): Energy is released in a nuclear reaction.
Reason (R): In any nuclear reaction the reactants and resultant products obey the law of conservation of charge and mass only.
→
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.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is NOT the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): When the observation point lies along the length of the current element, magnetic field is zero.
Reason (R): Magnetic field close to current element is zero.
→
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.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion: An alternating current shows magnetic effect.
Reason: Magnitude of alternating current varies with time.
→
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 (a), (b), (c) and (d) as given below.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is NOT the correct explanation of A.
  3. A is true, but R is false.
  4. A is false and R is also false.
Assertion (A): For the scattering of $\alpha$-partides at a large angles, only the nucleus of the atom is responsible.
Reason (R): Nucleus is very heavy in comparison to electrons.
→
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.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion (A): No two electric lines of force can intersect each other.
Reason (R): Tangent at any point of electric line of force gives the direction of electric field.
→
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.
  1. Both $A$ and $R$ are true, and $R$ is the correct explanation of $A.$
  2. Both $A$ and $R$ are true, but $R$ is not the correct explanation of $A.$
  3. $A$ is true but $R$ is false.
  4. $A$ is false and $R$ is also false.
Assertion $(A):$ The electric tines of forces diverges from a positive charge and converge at a negative charge.
Reason $(A): A$ charged particle free to move in an electric field always move along an electric line of force.
→
Assertion (A): Interference pattern is made by using yellow light instead of red light, the fringes becomes narrower. 
Reason (R): In Young's double slit experiment, fringe width is given by $\beta=\frac{\lambda D }{ d }$.
→