Army Public School &College (Boys) Saddar Karachi

                                                            PHYSICS HSC-I                                             Max. Marks: 15

Assignment for Pre-board

Note: Attempt all questions.

1. What are stationary waves? On what factors does the frequency of stationary waves in a stretched string depend?
2. Define the terms: crest, trough, compression, rarefaction node and antinode.
3. How the speed of a transverse in the string will change if its tension is made four times.
4. A standing wave is established in a 2.4m long string fixed at both ends. The string vibrates in 4 segments when driven at 200 Hz. Determine the wavelength and the fundamental frequency.
5. A guitar string has a linear density of 7.16 g/m and is under tension of 152 N. The fixed supports of the string are 89.4 cm apart. If it vibrates in three segments, calculate the speed, wavelength, and the frequency of the standing wave.
6. The length of pendulum is (1.5±0.01) m and the acceleration due to gravity is taken into account as (9.8±0.1) m/s². Calculate the time period of the pendulum with uncertainty in it.
7. If Ā =2î-6Ĵ-3ĸ̂ and B̄=4î +3Ĵ –ĸ̂, find a unit vector perpendicular to the plane of Ā and B.
8. Why the central ring of the Newton’s ring is dark? State the reason.
9. In the game of cricket, why is it easy to catch a ball with a high trajectory?
10. Describe Young’s double slit experiment. Derive the relevant expression and the formula for fringe             spacing.