# 11th Class Physics Public Answer Key

Physics subject of 11th class is a very easy and interesting subject from which we can gain knowledge a lot. If we understand it, it’s a very easy subject. Physics is just a natural process. It is based on experiments, mathematical analysis etc. 11th class physics will be very useful in higher studies for all. So here now we are going to discuss about the 11th class physics answer key.

## Choose the correct option

1. Identify the unit vector in the following:
2. 3. The range of sound that the human audible wavelength (speed of sound in air = 340 ms-1) is
4. a) 17m to 170m b) 0.17m to 17m c) 0,017m to 17m d) 1.7m to 17m

5. A column of air in a tube, closed at one end, resonates with an object vibrating 83 Hz. Then the length of the air column (speed of sound in air = 332 ms-1)
6. a) 1.5m b) 0.5m c) 2.0m d) 1.0m

7. Rms speed of hydrogen molecule at 27C
8. 9. Which one of the following in a scalar quantity
10. a) Speed b) velocity c) displacement d) linear momentum

11. Body length measured 3.51 m. If the accuracy is 0.01 m, the percentage measurement error is
12. a) 0.035% b) 351% c) 1% d) 0.28%

13. An object with mass of 20 kg, moving at a speed of 10 ms-1 on a horizontal smooth surface, collides with a massless spring with a constant spring of 5 N / m. When the mass stops after the impact, the compression distance of the spring is
14. a) 10m b) 50m c) 5m d) 20m

15. When a car takes a sudden left turn on a curved road, passengers are pushed towards the right due to
16. a) Absence of inertia b) inertia of direction c) inertia of motion d) inertia of rest

17. The efficiency of a heat engine working between the freezing point and boiling point of water is
18. a) 12.5% b) 6.25% c) 20% d) 26.8%

19. A spring with a force constant k is cut in half so that the length of one part is twice the length of the other. Then the longer piece has a force constant of
20. 21. The dimensional formula for moment of inertia
22. 23. The ratio between the rms speed and most probable speed of gas molecules at a given temperature
24. 25. If the distance between the earth and sun is twice its present value, the number of days in a year will be
26. a) 730 b) 1032 c) 64.5 d) 182.5

27. Moment of inertia of a solid cylinder of mass M, length l and radius r about its own axis is
28. ### 11th Class Physics Public Answers:

1. A
2. C
3. D
4. B
5. A
6. D
7. D
8. B
9. D
10. C
11. D
12. B
13. B
14. D

#### Conclusion:

These are the 11th class physics key papers. Which is very important. It is one of the key papers that will be very useful for everyone in higher studies. Everyone should practice these objective problems. It’s very important.