FRAVASHI TOWN JUNIOR COLLEGE, NASHIK
Work sheet - 5 April: 2025-26
STD: XII Science Sub: PHYSICS (54) Marks: 35
Chapter Name:- Superposition of waves
Section: A
Q.1. Select and write correct answers 5 Marks
(i) A string of mass 0.1 kg is under a tension 1.6 N the length of the string is 1 m. a
transverse wave starts from end of the string the time taken by the wave to reach the other
end is
(a) 0.35 s (b) 0.25 s (c) 0.30 s (d) 0.20 s
(ii) Two uniform wire of same material are vibrating under the same tension. If the first
overtone of first wire is equal to the 2nd overtone of 2nd wire and radius of the first wire is
twice the radius of the 2nd wire then the ratio of length of first wire to 2nd wire is
(a) 1:9 (b) 9:1 (c) 1:3 (d) 3:1
(iii) Two particles are executing shm of same amplitude and frequency along the same
straight line path the pass each other when going in opposite directions each time their
displacement is half the amplitude the phase difference between them is (sin 30o = 0.5)
2𝜋 3𝜋𝑎 𝜋𝑎 2𝜋𝑎
(a) 3 (b) 5 (c) 5 (d) 5
(iv) The equation of progressive wave is Y = asin 2π (nt – x/5) the ratio of maximum particle
velocity to wave velocity is
3𝜋𝑎 4𝜋𝑎 𝜋𝑎 2𝜋𝑎
(a) 5 (b) 5 (c) 5 (d) 5
(v) The velocity of sound in air when temperature is halved and pressure doubled will be
(a) 234.2 m/s (b) 466.62 m/s (c) 165 m/s (d) 330 m/s
Q.2. Answer the following 4 Marks
(i) A wave is represented by an equation y = A sin (Bx + Ct) given that the constants A, B
and C are positive can you tell in which direction the wave is moving?
(ii) Give two examples of stringed instruments
(iii) Define end correction
(iv) State Doppler Effect
Section: B
Attempt any Five 10 Marks
Q.3. Distinguish between progressive wave and stationary wave
Q.4. State the application of beats
𝑛1𝑙1 − 𝑛2𝑙2
Q.5. Prove that e =
2 (𝑛2 − 𝑛1)
Q.6. For a stationary wave set up in a string having both ends fixed what is the ratio of the
fundamental frequency to the second harmonic?
Q.7. A standing wave is produced in a tube open at both ends the fundamental frequency is
300 Hz what is the length of tube?
Q.8. A standing wave is produced in a tube open at both ends the fundamental frequency is
300 Hz what is the length of tube? (Speed of the sound = 340 m/s)
Section: C
Attempt any Four 12 Marks
Q.9. The amplitude of wave is represented by
𝑡 𝑥
Y = 0.2 sin 4π ( - ) find (i) wavelength (ii) frequency (iii) amplitude of wave
0.08 0.8
Q.10. A sound wave in a certain fluid medium is reflected at an obstacle to form a standing
wave the distance between two successive nodes is 3.75 cm if the velocity of sound is
1500 m/s find the frequency
Q.11.Show that only odd harmonics are present in the vibrations of air column in a pipe
closed at one end
Q.12. Derive an expression for equation of stationary wave on a stretched string
Q.13. Distinguish between free vibrations and forced vibrations
Section: D
Attempt any One 4 Marks
Q.14. Find the amplitude of the resultant wave produced due to interference of two waves
given as y1 = A1 sin ꞷt y2 = A2 sin (ꞷt + ɸ)
Q.15. What are harmonics and overtones
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