Class 9 heat revision questions

 Second term weekly test revision questions

Q1.a) what do you mean by degradation of energy?

b) why a person should use bio- char stoves for cooking?

Q2.a) write two policy measures to check global warming.

b) How green house gases and global warming are related to each other.

Q3.a) what percentage of total electrical power generated in India is obtained from nuclear power plants? Name two places in India where electricity is generated from nuclear power plants.

b) write three disadvantage of using solar panels?

Q4.a) Describe an experiment to show that water has maximum density at 4 degree Celsius. What important consequences follow from this Peculiar property of water? Discuss the importance of this phenomena in nature.

b) what do you mean by energy flow in ecosystem in form of a food chain. Explain it With the help of a suitable diagram.

Class8 light revision questions

 Second term weekly test revision questionaires

Q1.a) what do you mean by absolute refractive index?

b) what do you understand by refraction of light?

Q2.a) state two uses of concave mirror.

b) what is a real image? Why it cannot be formed by a convex mirror?

Q3.a) Draw a diagram showing the refraction of light ray from water to glass.label on it the incident Ray, angle of incidence and the angle of refraction.

b) A coin placed at the bottom of vessel appears to be raised when water is poured in the vessel. Explain it with the help of suitable diagram.

Q4.a) Draw a separate diagrams for the formation of a virtual image of an object by a concave mirror and a convex mirror. State the difference of the two images.

b) A driver cannot use a concave mirror as a rear view mirror. Explain the reason with the help of a ray diagram

Class7heat revision question

 Final term weekly test revision questions

Q1.a) why on a hot day the Steel chair will feel warmer than a wooden chair?

b) water is a ....... of heat.

Q2.a) why we use woolen clothes in winter?

b) why is the freezing chest in a refrigerator fitted near its top?

Q3.a) write three applications of conductor in our daily life.

b) convert 512°F to the Kelvin scale.

Q4.a) draw a well labelled diagram of a thermometer and explain its working.

b) what do you mean by convection current? Demonstrate Convection in a liquid with suitable diagram and explain it.

Class 6 machine revision questions

Final term weekly test revision questionnaire

Q1.a) what do you mean by efficiency of a machine?

b) what is an effort arm.

Q2.a) Define the term effort and load in relation to a machine.

b) what is a wedge? Write its use.

Q3.a) draw a neat labelled diagram of a hand pump. State it's class of lever. Write its mechanical advantage.

b) state the principle of a machine and explain it with the help of a suitable example.

Q4.a) define lever. Explain its types with the help of a suitable diagram.

b) mechanical advantage of a lever is 5. How much load can be lifted by applying an effort of 20 Newton? State the class of lever And draw its suitable diagram.

Electricity and Magnetism 2024 practice questions

 1. Objective type questions:

1.1 which of the following is the sure test of magnetism?

A. Repulsion

B. Attraction

C. Direction

D. Contraction

1.2 which of the following is not a magnetic material?

A. Iron

B Nickel

C. Cobalt

D. Stainless steel

1.3 which of the following involves use of electric current as a magnet?

A. Heating water in an electric kettle

B. Separating iron scrap

C. Solar heater

D. Using a switch

1.4 in the given electric circuit, which materials can be placed betweenA & B so that bulb would glow?

   1 comb.      2. Copper spoon   

3. Wooden spoon.  4. Pencil lead

A. 1&4

B.2&4

C.2&3

D.1,3&4

1.5 which of the following is not a correct statement?

A. A magnet is attractive in nature.

B. Repulsion is a sure test of magnetism.

C. When electricity is passed through a wire, it behaves like a magnet.

D. In an Electromagnet, the core is made up of copper.

2. Fill in the blanks:

2.1 SI unit of current is ....     .....

2.2 an electric bell is an application of the phenomenal of.............

2.3 in household circuit, different appearances are connected in........  

2.4 ............. was the first magnet discovered by the man.

2.5 the force with which a magnet attracts a magnetic substance is called..........

Practice questions for class 8 based on electricity 2024

 1. Multiple choice questions:

1.1 conductors can conduct electricity because they have free

A. Protons

B. Electron

C. Neutrons

D. Both A & B.

1.2 lightning cannot Strike

A telephone cords

B. Electrical wires

C. Metal pipes

D. Plastic toy

1.3 a miniature circuit breaker is an automatically operated

A. Electrical switch

B. Socket

C. Battery

D. Plug

1.4 the outer body of a switch is made of

A. Bakelite

B.Brass

C.coppet

D.plastic

1.5 the colour of live wire is

A.yellow

B.red

C.blue

D.green

2. Fill in the blanks:

2.1 the working of fuse depends on the....... of the current.

2.2 electric tools used should have proper..... handles.

2.3 Avoid ....... wires,cables and connections 

2.4 The ..... . May cause melting of wires with the risk of Fire.

2.5 the electric shock occurs when the..      flows through the body 

3. Define the following terms:

3.1 earthing

3.2 miniature circuit breaker

3.3 charging by conduction

3.4 battery

3.5 overloading of electric circuit

3.6 electroscope

3.7 short circuit

3.8 electric fuse

3.9 lightning

3.10 kilowatt - hour

4. Answer the following in brief:

4.1 name the sub atomic particles of an atom. What kind of charges are present on them.

4.2 list the methods of charging and object.

4.3 how do objects gets charged?

4.4 what do you mean by atmospheric electricity?

4.5 what is an electric circuit. Draw its diagram.

5. Answer the following questions in detail:

5.1 describe the principle and working of an electric fuse.

5.2 what is the reason of short circuit and overloading?

5.3 what is electric fuse and its basis of working?

5.4 explain law of conservation of charge with the help of an example.

5.5 write six precautions to be taken while handling electricity.

6 give reasons:

6.1 what is the reason of static electricity?

6.2 what is the reason for getting an electric shock?

6.3 why do we install lightening conductor on tall buildings?

6.4 how do conductors conduct electricity,

6.5 while charging by friction, how can the charge be acquired by rubbing to different objects together?

7. Concept based questions

7.1 explain the working of an electroscope.

7.2 how does Benjamin franklin's kite and key experiment demonstrated the connection between lightning and electricity?

7.3 why does a com run through dry hair attract pieces of paper?

8. Analysis based questions

8.1 why should we keep away from water when there is lightning? Analyse the fact and explain.

8.2 earthing system protects us from electric shock. However some devices do not have Earth wire. Why is it a wrong practice?Explain it.

9.Hot questions:

9.1 why are there two metallic plates attached to the bell jsr of an electroscope?

9.2 pure water does not conduct electricity whereas tap water can.explain.

9.3 why do leaves of a gold leaf electroscope diverge when given a charge?

9.4 how does charging of an object occur by conduction?

9.5A is a metallic rod carrying an access of negative charge,B is a positively charged wooden sphere. What will happen if we touch A with B?

Class 6 phy. Ch.6 magnet

 1. Explain discovery of magnets.

2.write four differences between a natural & artificial magnet .

3. Define artificial magnet. Explain its different types with suitable diagram.

4. What are magnetic and non magnetic substances. Explain it with suitable examples.

5. Write two characteristics of a magnet. Explain these two characteristics with suitable example and diagram.

6. Write four properties of a magnet.

7. What do you mean by magnetic field of a magnet. How will you prove that a magnetic field exist around a magnet?

8. How will you prove that Earth behaves like a huge magnet? Draw a diagram to show the earth magnetic field in a limited space.

9. Explain four methods of making a magnet with the help of suitable examples and diagram.

10. Distinguish between temporary and permanent magnets. write at least five differences.

11. What is an electromagnet ? How it can be prepared? Draw its diagram. Write two factors affecting strength of an electromagnet.

12. Write five uses of magnets.

13. Why a magnet should be cared and stored in a proper way? Draw a diagram to show storage of :

A. Bar magnet

B. Horse shoe magnet

14. What do you mean by demagnetisation of a magnet. Write five ways in which A magnet can be demagnetised.

15. How will you find polarity of an Electromagnet when current passes through it?

16. Why artificial magnets are preferred over natural magnet? At least 3 points.

17. Differentiate between single touch and double touch method of making a magnet.