SOUND

Name: Assignment - VI Class: X Subject: Physics

SOUND


I Choose the correct answer

1. Velocity of sound in air is ( )
(a) V = p/Pv (b) V = pP/v (c) V = vP/p (d) V = P/p
2. In a resonating air column experiment with a closed-end tube, first resonance occurs when the length of the air column is 10 cm. Second resonance occurs at ( )
(a) 5 cm (b) 20 cm (c) 30 cm (d) 40 cm
3. A medium transmits a sound wave through it by virtue of its ( )
(a) Elasticity (b) Inertia (c) Density (d) Elasticity and inertia
4. The wavelength of a wave is the ( )
(a) Distance between two vibrating particles with a phase difference of .
(b) Distance between a crest and a consecutive trough
(c) Distance between any two particles vibrating in same phase
(d) Distance between any two particles vibrating out of phase by /2
5. Distance between a node and the next anti node in a stationary wave is 10cm. Then the wavelength is ( )
(a) 5cm (b) 40cm (c) 20cm (d) 10cm
6. In a stationary wave, the point at which the displacement is maximum is called ( )
(a) Node (b) Anti node (c) Crest (d) Trough
7. Always an anti node is formed at the ( )
(a) Closed end (b) Open end (c) Either at closed or open end (d) None
8. Periodic vibrations of decreasing amplitude are called ( )
(a) Forced vibrations (b) Damped vibrations (c) Resonance (d) Natural vibrations
9. Velocity of sound is minimum in ( )
(a) Steel (b) Vacuum (c) Water (d) Air
10. The Velocity of sound in air can be determined experimentally using the formula ( )
(a) V =  (b) V = P/p (c) V = Cp/Cv (d) V = 2(I2 – I1)

II Fill in the blanks

1. Every system has its own frequency called ___________________
2. The vibrations that take place under the influence of an external periodic force are called __________________
3. When two waves of equal frequency and amplitude travel in opposite direction _________________ are formed.
4. A wave undergoes a phase change of __________________ on reflection.

5. Distance between two successive nodes or antinodes is ________________
6. Distance between a node and the next anti node is _____________
7. Particles undergo minimum displacement at _________________ in a stationary wave.
8. The velocity (V) of sound wave of frequency () and wavelength () is given by __________________
9. If the displacement of particles of medium is at right angles to the direction of propagation of wave, then the wave is said to be a________________ wave.
10. If the displacement of particles of a medium is parallel to the direction of propagation of the wave then the wave is said to be a ____________________ wave.

III 1 Mark questions

1. What is a damped vibration?
A. Periodic vibrations of decreasing amplitude are called damped vibrations.
2. Define resonance?
A. If one of the two bodies of the same natural frequency is set into vibration, the other body also vibrations are called resonance.

IV 2 Marks questions

1. What is a resonating air-column?
2. Explain the terms ‘natural’ and ‘forced vibrations’
3. Describe an experiment to demonstrate resonance and forced vibrations

V 4 Mark questions

1. Describe a few incidents of resonance phenomenon observed in your day-to-day life.
2. Distinguish between progressive and stationary waves.

water aloneshouldnot be kept in a microwave

water explodes in microwave oven why and how?
watch the experiment at www.stevespanglerscience.com/experiment/exploding-water-in-the-microwave

Class: X QUARTELY EXAMINATION SUB: Mathematics

Section – I
I Answer the following 5 questions, choosing atleast 2 from each group. (5x4=20)
Group-A

1. Let A, B are two subsets f a universal set U. show that A  B = A- B’ = B –A’.
2. Let f: R- {2}  R be defined by f(x) = 2x +1/x-2. Show that f(2x+1)/(x-2)
3. Find the sum and the product of the roots of the following equation. 2x2-7x+3= 0
4. Find the number which is less than its square by 132.

Group-B
5. Given a GP with a= 729 and 7th term is 64. Determine S7.
6. If there are n arithmetic means between a and b find common difference “d.”
7. Find the mode when median is 125.6 and mean is 128.
8. If A =
Show that A-1= 4I-A

Section –II
II Answer any four questions. (4x2=8)
9. State Pythagorus theorem.
10. State onto function.
11. State basic theorem of sets.
12. Define singular matrix.
13. Find the seventeenth term in series if Tn=n (n+3)/(n+2).
14. Write 3x3 identity matrix. Section –III
III Answer any four questions choosing atleast 2 from each group (4x8=32)
Group-A
15. Show that A(B  C) = (AB)  (A  C) for any three sets A, B, C.
16. Given f(x) = (x-1), g(x) =x2-2 h(x)=x3-3 find (fog)oh and fo(goh).
17. A play field is 100 m by 60m, has a footpath all around it on the outside. What is the width of the path if its area is 3/5 of the area of the field?
18. Using the remainder theorem find the factors of x4+3x3-7x2-27x-18.

Group-B
19. State and prove basic proportionality theorem.
20. Find sum to n terms of the series 0.5+0.55+0.555+------
21. The A.M, G.M. and H.M. of two numbers are A, G, H respectively. Show that
A  G H.
22. Solve by Cramer’s method: x+5y = 17 and 5x+y = 13.
Section IV

IV Answer any one of the following .

24. Draw a circum circle of triangle ABC when BC = 6cm, ∟B=55o, ∟C= 70o.
25. Using the graph y=x2, solve x2-x-6=0.