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#### Nature of Physical World and Measurement Important Question Paper

11th Standard

Reg.No. :
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Physics

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. One of the combinations from the fundamental physical constants is ${{hc}\over{G}},$ The unit of this expression is

(a)

Kg2

(b)

m3

(c)

S-1

(d)

m

2. If the error in the measurement of radius is 2%, then the error in the determination of volume of the sphere will be

(a)

8%

(b)

2%

(c)

4%

(d)

6%

3. If $\pi=3.14,$ then the value of ${\pi}^{2}$ is

(a)

9.8596

(b)

9.860

(c)

9.86

(d)

9.9

4. Astromical Scale is dealt with the _________ Physics

(a)

Mesoscopic

(b)

Microscopic

(c)

Macrospic

(d)

None

5. Microscopic group of Physics dealt with the study of ____________.

(a)

classical physics

(b)

statistical mechanics

(c)

fluid mechanics

(d)

quantum physics

6. 5 x 2 = 10
7. The radius of the circle is 3.12 m. Calculate the area of the circle with regard to significant figures.

8. Assuming that the frequency y of a vibrating string may depend upon (i) applied force (F) (ii) length (I) (ill) mass per unit length (m), prove that $\gamma\infty{{1}\over{l}}\sqrt{{{F}\over{m}}}$using dimensional analysis.

9. The measurement value of length of a simple pendulum is 20cm known with 2mm accuracy.  The time for 50 oscillations was measured to be 40 s within Is resolution. Calculate the percentage accuracy in the determination of acceleration due to gravity 'g' from the above measurement.

10. What are the steps involved in scientific method?

11. What is Physics?

12. 5 x 3 = 15
13. If humans were to settle on other planets, which of the fundamental quantities will be in trouble? Why?

14. Name the SI unit for electric current and give a definition for it.

15. Name the SI unit for Luminous intensity and give a definition for it.

16. Find the dimensions of a and b in the formula $\left[ P+{{a\over V^2}} \right][V-b]=RT$ where P is pressure and V is the volume of the gas

17. Show that $({P}^{-5/6}{ρ}^{1/2}{E}^{1/3})$ is of the dimension of time. Here P is the pressure, $ρ$ is the density and E is the energy of a bubble)

18. 4 x 5 = 20
19. What do you mean by propagation of errors? Explain the propagation of errors in addition and multiplication.

20. Write the rules for "Rounding off" with example

21. The length of a rod as measured in an experiment was found to be 3.48m, 3.46m, 3.49m, 3.50m and 3.48 m. Find the average length, the absolute error in each observation and the percentage error.

22. If the value of universal gravitational constant in SI is 6.6$\times$10-11 Nm-2 kg-2,then find its value in CGS System.