Lakhmir Singh & Manjit Kaur - Physics

Book: Lakhmir Singh & Manjit Kaur - Physics

Chapter: 3. Sources of Energy

Subject: Physics - Class 10th

Q. No. 17 of Short Answer Type Questions-Pg-157

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17

Write Einstein's mass-energy equation. Give the meaning of each symbol which occurs in it.

Einstein's mass-energy equation is, E=mc2,

The equation is derived directly from Einstein’s Special Theory of Relativity


Each of the letters of E = mc2 stands for a particular physical quantity. Writing them out in full we get:


E = energy (measured in joules, J)


m = mass (measured in kilograms, kg)


c = the speed of light (measured in meter per second, ms-1)


Chapter Exercises

Very Short Answer Type Questions-Pg-121
Very Short Answer Type Questions-Pg-130
Very Short Answer Type Questions-Pg-140
Very Short Answer Type Questions-Pg-148
Very Short Answer Type Questions-Pg-156
Very Short Answer Type Questions-Pg-161
Short Answer Type Questions-Pg-122
Short Answer Type Questions-Pg-131
Short Answer Type Questions-Pg-140
Short Answer Type Questions-Pg-148
Short Answer Type Questions-Pg-157
Short Answer Type Questions-Pg-161
Questions Based on High Order Thinking Skills (HOTS)-Pg-123
Questions Based on High Order Thinking Skills (HOTS)-Pg-132
Questions Based on High Order Thinking Skills (HOTS)-Pg-142
Questions Based on High Order Thinking Skills (HOTS)-Pg-150
Questions Based on High Order Thinking Skills (HOTS)-Pg-159
Long Answer Type Questions-Pg-122
Long Answer Type Questions-Pg-131
Long Answer Type Questions-Pg-141
Long Answer Type Questions-Pg-149
Long Answer Type Questions-Pg-157
Multiple Choice Questions (MCQs)-Pg-122
Multiple Choice Questions (MCQs)-Pg-131
Multiple Choice Questions (MCQs)-Pg-141
Multiple Choice Questions (MCQs)-Pg-149
Multiple Choice Questions (MCQs)-Pg-158
Multiple Choice Questions (MCQs)-Pg-161

More Exercise Questions

14

What is nuclear fission? Explain with an example. Write the equation of the nuclear reaction involved.
15

What is nuclear fusion? Explain with an example. Write the equation of the reaction involved.
15

Why are very high temperatures required for fusion to occur?
16

What is the nuclear fuel in the sun? Describe the process by which energy is released in the sun. Write the equation of the nuclear reaction involved.
17

Write Einstein's mass-energy equation. Give the meaning of each symbol which occurs in it.
17

If 25 atomic mass units (u) of a radioactive material are destroyed in a nuclear reaction, how much energy is released in MeV?
18

What is the source of energy of this sun and other stars?
18

Describe the working of a hydrogen bomb.
18

What is common between the sun and a hydrogen bomb?
19

What will happen if slow moving neutrons are made to strike the atoms of a heavy element 23592U? What is the name of this process?
19

Write a nuclear equation to represent the process which takes place.
19

Name one installation where such a process is utilized.
20

What are the advantages of nuclear energy?
20

State the disadvantages of nuclear energy.
21

The following questions are about the nuclear reactor of a power plant.

a) Which isotope of uranium produces the energy in the fuel rods?


b) Will the fuel rods last forever?


c) Is the energy produced by nuclear fission or nuclear fusion?


d) What is the purpose of using the graphite moderator ?


e) What is the function of boron rods in the nuclear reactor?


f) Why is liquid sodium (or carbon dioxide gas) pumped through the reactor?
22

In the reactor of a nuclear power plant, name the material which is used :

(a) As a moderator


(b) To absorb radiations


(c) In the fuel rods


(d) In the control rods


(e) To carry away heat
23

In the nuclear reactor of a power plant:

(a) How do control rods control the rate of fission?


(b) How is heat removed from the reactor core, and what use is made of this heat?
24

How does inserting the control rods in the graphite core affect the fission in the reactor? Explain your answer.
25

What are the advantages and disadvantages of using nuclear fuel for generating electricity ?

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