science general knowledge 🤠

            Science General Knowledge

1. Does friction oppose motion?

Ans: Friction only opposes relative motion.

2.Does earth move around the sun in circular orbit?

Ans: Earth orbits around the sun in an elliptical orbit.

3. What is the most important part of the heart❤️? 

Ans: Pacemaker.

4. When did Big Bang occur?

Ans: About 13.8 billion years ago.

5. What happens in cancer?

Ans: Cancer leads to uncontrolled growth of cells.

6. For what discovery was Einstein awarded the Nobel prize?

Ans: Photoelectric effect 

7. What are four types of waves?

Ans: Matter wave, mechanical wave, electromagnetic wave and gravitational wave

8. Write seven em waves in order decreasing wavelengths.

Ans: Radio wave, Microwave, infrared wave, visible light, ultraviolet wave, x-ray, gamma ray.

9. On what fact does the electron microscope depend on?

Ans: Wave nature of electron.

10. What is the energy of a single photon?

Ans: It is given by E=hf 

        where f is the frequency of the photon.

11. How many satellites does Jupiter have?

Ans: 80

12. Is time affected by motion?

Ans: Yes the time is affected by motion as proposed by Einstein in his special theory of relativity.

13. Write three physical phenomena that prove the particle nature of light.

Ans: Photoelectric effect, Compton effect and Blackbody radiation.

14. Write the names of Maxwell's equations.

Ans: Gauss law of electrostatics, Gauss law of magnetism, Faraday law of electromagnetic induction and Ampere-Maxwell law.

15. What is gravity at the centre of the earth?

Ans: Zero.

16. How is black hole formed?

Ans: Black hole is formed by the gravitational collapse of star.

17. Write names of three galaxies.

Ans: Milky way, Andromeda and M87.

18. Write three relativistic Invariant quantities.

Ans: Charge, Speed of light and space-time interval.

19. Name the black hole located at the centre of Milky way galaxy.

Ans: Sagittarius A*

20. Who won twice Nobel prize?

Ans: Marie Curie.

21. What unites electricity and magnetism? 

Ans:  Only four Maxwell's equations unify these two vast disciplines.

22. What are the four fundamental forces of nature?

Ans: There are four fundamental forces of nature; gravity,weak nuclear force, electromagnetic force and strong force.

Gravity: The force of attraction due to mass is called gravitational force.

Weak nuclear force: The force that takes part in nuclear decay like beta decay .

Electromagnetic force: The force that a charge experience in electromagnetic field.

Strong force: The force that binds quarks together.

23. What is interference?

And: The phenomenon of formation of maximum intensity at some points and minimum intensity at some other points when two or more waves of equal frequency having constant phase difference arriving at a point simultaneously and superimposing with each other,is know as interference.