Question
What do you understand by controlled and uncontrolled chain reactions?

Answer

Controlled chain reaction : If the chain reaction of fission can be controlled in such a way that it neither increases nor decreases, that is, such a level of reaction is maintained such that the energy released per second always remains less than the limit of explosion. This is called controlled chain reaction. This type of reaction is used in the production of electrical energy. Controlled chain reaction is the fundamental basis of 'nuclear reactor'.
Uncontrolled chain reaction : In this reaction, on average, more than one neutron takes part in the process of fission out of the neutrons obtained from each fission. Here $K >1$. Due to this, the rate of fission of nuclei increases rapidly and within a few moments tremendous energy is released and causes a massive explosion. This reaction takes place in the atomic bomb.

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

  1. Three point charges q, -4q and 2q are placed at the vertices of an equilateral triangle ABC of side ‘l’ as shown in the figure. Obtain the expression for the magnitude of the resultant electric force acting on the charge q.

  1. Find out the amount of the work done to separate the charges at infinite distance.
Write the difference between alternating current and voltage.
Find the charge supplied by the battery in the arrangement shown in figure.

The magnifying power of a simple microscope is given by $1+\frac{\text{D}}{\text{f}},$ where D is the least distance for clear vision. For farsighted persons, D is greater than the usual. Does it mean that the magnifying power of a simple microscope is greater for a farsighted person as compared to a normal person? Does it mean that a farsighted person can see an insect more clearly under a microscope than a normal person?
A flint glass prism and a crown glass prism are to be combined in such a way that the deviation of the mean ray is zero. The refractive index of flint and crown glasses for the mean ray are 1.620 and 1.518 respectively. If the refracting angle of the flint prism is 6.0°, what would be the refracting angle of the crown prism?
Define semiconductors on the basis of energy band theory. What are the charge carriers in semiconductor? What do semiconductors start behaving like at absolute zero temperature?
Write two important considerations used while fabricating a Zener diode. Explain, with the help of a circuit diagram, the principle and working of a Zener diode as voltage regulator.
A bulb rated 60W at 220V is connected across a household supply of alternating voltage of 220V. Calculate the maximum instantaneous current through the filament.
  1.  

  1.