# Class 10 Physical Science Important Topics And Important Questions

Class 10 physical science subject is a very important and easy subject. Physics helps us to understand how the world works around us. It deals with fundamentals. It helps us to organise the universe. Physics helps us to express our creativity and also helps us to see the world in a new way. Learning physics is very important. Physics provides us quantitative and analytical skills. This world is nothing without physics. The things which we do in our daily life are related to physics. Physics is the basis for all modern technology. Physics is a very easy subject and it opens the door for many career options. So now we are going to discuss some important topics and questions.

## Class 10 physical science Important

1. Electricity
2. Light- Reflection and Refraction
3. Sources of energy
4. Human eye and the colourful world
5. Magnetic effects of electric current

### Important questions-Electricity:

1. How do insulators differ from conductors?
2. Draw the diagrams of open and closed circuits and differentiate between them?
3. Define parallel connection and series connection?
4. Write disadvantages of heating effect current?
5. Write advantages of heating effect current?
6. What is an electric current?
7. Define potential difference and give units for it?
8. Find the expression for calculating the heat?
9. Calculate the resistance for given information a wire is 1m long, 0.2mm in diameter and has resistance of 10?
10. Calculate the cross-sectional area of a wire with a length of 2m, a resistance of 25 and a wire material resistance of 1.84*10-6?
11. Calculate the energy consumed by a 120W toaster in 20min?
12. Name any two metals which are highly resistant and explain what is resistant of conductors?
13. Explain what is the reason why tungsten metal is used in bulbs but not in fuse wires?
Define Watt and Volt?

### Important questions-Light reflection and refraction

1. What is meant by magnification of a plane mirror?
2. Explain the reason behind why paper catches the fire when we use a convex lens to focus sunlight?
3. Explain what is meant by silvering of mirrors?
4. Explain what is meant by refractive mirror?
5. Give formulas for lens and power of lens?
6. Calculate the refractive index of kerosene with respect to water when the refractive index of water is 1.33 and kerosene is 1.44?
7. To watch activities of customers in big shopping stores which kind of mirrors are used?
8. Give a mirror image of the word Ambulance?
9. What is the mirror’s radius of curvature?
10. The magnification produced by a plane mirror is+1. What does it mean?

## Important questions-Sources of energy

1. The cost of generating electricity at TPP Bihar is lower than in Gujarat. Can you prove this statement and provide reasons?
2. There are two solar cookers, out of two one was covered and the other is opened. Which one of the two will be efficient and why?
3. The surface area of the concentrator type solar heater is 5 m2. It can reflect 80% of solar radiation and absorb the rest. Calculate the energy approved by the heater, because it will be concentrated at 2 hours if solar energy has been delivered to them of 0.4 kJ / m2s.?
4. List any three energy sources that are considered to be inexhaustible. State three reasons in support of your answers?
5. Why is there so much emphasis on switching from petrol / diesel cars to CNG cars?
6. List any two effects increase in the demand for energy is affecting our environment adversely?
7. How waste is produced in nuclear power plants are different from those produced in thermal power plants and what happens to a waste from a nuclear plant system?
8. What is meant by acid rains? And what are the harmful effects of it?
9. In a solar cooker what are the uses of black painted surfaces?
10. In the treatment of cancer what is the energy used?
11. What is the fullform of CNG?
12. What energy does the earth’s upper atmosphere receive per square meter per second?

### Important questions-Human eye and the colourful world

1. What is the diameter of a human eye?
2. What are the functions of the crystalline lens of the human eye?
3. In what types of eye defects is the distal point of the eye reduced?
4. In the evening why do birds fly back to their nest mention the reasons?
5. Why do we take time to find objects when we enter a dimly lighted room from outside in the sun?
6. Why does a ray of light split when passed from prism?
7. Why doesn’t the planet appear twinking?
8. State the reasons why we can’t see the things closer to our eyes?
9. Explain the reason that when we see any object through the hot air over the fire, it appears to be away, moving slightly?
10. Explain the reason that, on a clear day, why does the sky appear blue in colour?

## Important questions-Magnetic effects on electric current

1. The MCB of a Rupa’s room is tripped and keeps on tripping again and again. If it is a domestic circuit, what would be the reason for this phenomenon?
2. Explain any three appliances that function on Fleming’s left hand rule?
3. What is needed to convert the dynamo to alternating current?
4. What are the applications of solenoid?