Home
Class 12
PHYSICS
In a nuclear reactor, moderators slow do...

In a nuclear reactor, moderators slow down the neutrons which come out in a fission process. The moderator used have light nuclei. Heavy nuclei will not serve the purpose because

A

they will break up

B

elastic collision of neutrons with heavy nuclei will not slow them down

C

the net weight of the reactor would be unbearably high

D

substances with heavy nuclei do not occur in liquid or gaseous state at room temperature .

Text Solution

Verified by Experts

The correct Answer is:
b
During an elastic collision between two particles, the maximum kinetic energy is transferred from one particle to the other when they have the same mass. Therefore , heavy nuclei will not serve the purpose because elastic collision of neutrons with heavy nuclei will not show them down.
Promotional Banner

Topper's Solved these Questions

  • NUCLEI

    NCERT FINGERTIPS ENGLISH|Exercise ASSERTION & REASON|15 Videos

  • NUCLEI

    NCERT FINGERTIPS ENGLISH|Exercise Atomic Masses|3 Videos

  • NUCLEI

    NCERT FINGERTIPS ENGLISH|Exercise HOTS|7 Videos

  • MOVING CHARGES AND MAGNETISM

    NCERT FINGERTIPS ENGLISH|Exercise Assertion And Reason|15 Videos

  • PRACTICE PAPPER

    NCERT FINGERTIPS ENGLISH|Exercise Practice Paper 3|50 Videos

Similar Questions

Explore conceptually related problems

Calcium rods are used in nuclear reactors to slow down the neutrons taking part in the fission process

The Process by which a heavy nucleus splits into light nuclei is known as-

Which of the following is used as a moderator in nuclear reactors?

In a nuclear reactor, a neutron of high speed (~~10^(7)ms^(-1)) must be slowed down to 10^(3)ms^(-1) so that it can have a high probality of interacting with isotipe _92U^(235) and causing it to fission. Show that a neutron can lose most of its K.E. in an elastic collision with a light nuclei like deuterium or carbon which has a mass of only a fewe times the neutron mass. The material making up the light nuclei usually heavy water (D_(2)O) or graphite is called modertaor.

Water is used as a moderator in nuclear reactor. Moderator is a light substance that absorb neutrons.

Heavy water is used as moderator in a nuclear reactor. The function of the moderator is

Heavy water is used as moderator in a nuclear reactor. The function of the moderator is

Heavy water is used as moderator in a nuclear reactor. The function of the moderator is

From study of elastic collision we understand that if two colliding particles have equal masses they interchange their velocities and energy transfer is maximum if they have equal masses and one is at rest w... other. This principle can be easily used in nuclear reactor to select a moderator. If m_(1)=m_(2)=m and m_(2) at rest then m_(1) will stop after colliding with m_(2) and m_(2) will move with velocity of m_(1) . In case of nuclear reactor we used a moderator such that neutrons can be slowed down. With above reference answer the following questions Which is correct statement

Ordinary water is not used as a moderator in nuclear reactors because