Physics Chapter 1


1. 0.5 A= 500mA.

2. The dimension of plank constant(h) is [ M L2 T-1 ].

3. Number of significant figures in 4.0030 are 5.

4. The angle subtended  by the circumference of circle at center of circle is 2π radians or 1 rev or3600.

5. The angle subtended at the center of the sphere by its surface area = 4π steradian.

6. One atto = 10-18.

7. The circumference of circle divided by diameter of the circle is called π.

8. Plane angle subtended at center of circle by an arc of length equal to its radius Radian.

9. Angle subtended at center of circle by an arc of length 1/360 of the circumference of the circle  Degree.

10. Carelessness, improper knowledge and incorrect reading causes Personal error.

11. Faulty apparatus or poor calibration and zero error causes Systematic error.

12. Change in temperature, voltage and humidity error causes Random/accidental error.

13. Random error is also called Statistical error.

14. The final result should contain as much significant figure as that contained by  Least significant figure.

15. Magnitude of frictional error or relative error  Accuracy.

16. Force, Energy and acceleration are Dimensional variable.

17. Light speed in vacuum, plank’s constant, gravitational constant and ideal gas constant are  Dimensional constant.

18. Plane angle, solid angle, strain and co-efficient of friction are Dimensionless variable.

19. Pure numbers and π are Dimensionless constant.

20. The uncertainty recorded in radius of sphere is 1.6% .uncertainty in area of sphere is  3.2%  (Area=πr2 ).

21. 10.00300 ,no of significant figures are 7.

22. A precise measurement is one which has Absolute precision.

23. Particle physics concern with the particles of the  Matter.

24. Computer chips are made up of  Silicon. 

25. SI unit of work is  N m. 

26. The dimension of work is same to that of  Energy.

27. Steradian is  Supplementary unit.