Chapter-12 : Science Class 9 MCQ’s with Answers
Q1.Which of the following is carried by the waves from one place to another
(a) Velocity
(b) Work
(c) Energy
(d) Mass
Ans: Energy
Q2. In a slinky (i.e., a long spring) which of the following types of waves can be generated
(a) Standing only
(b) Longitudinal only
(c) Both A and B
(d) None of these
Ans: Standing only
Q3. In gases a sound wave is
(a) Longitudinal only
(b) Transverse only
(c) both A and B
(d) None of these
Ans: Longitudinal only
Q4. In a transverse wave, the individual particle of the medium move
(a) Perpendicular to the direction of travel
(b) In circle
(c) Parallel in the direction of travel
(d) In ellipses
Ans: Perpendicular to the direction of travel
Q5. A body produces sound only if it is
(a) Made of glass
(b) Made of aluminium
(c) Vibration
(d) Made of iron
Ans: Vibration
Q6. The SI unit of amplitude of motion is
(a) mm
(b) cm
(c) A
(d) m
Ans: m
Q7. If a wave complete 20 vibration in 2.5s, then its frequency is
(a) 200 Hz
(b) 50 Hz
(c) 20 Hz
(d) 8 Hz
Ans: 8 Hz
Q8. A wave completes 24 cycles in 0.8 s. The frequency of the wave is
(a) 30 Hz
(b) 24 Hz
(c) 12 Hz
(d) 8 Hz
Ans: 30 Hz
Q9. A fan is marked 900 r.p.m.(revolution per minute). What is the frequency of movement of its blades
(a) 900 Hz
(b) 90 Hz
(c) 15 Hz
(d) 10 Hz
Ans: 15 Hz
Q10. The frequency of sound waves can be expressed in
(a) Second
(b) Cycle
(c) Metre per second
(d) Cycle per second
Ans: Cycle per second
Q11. In the above figure which pair of particle are out of phase
(a) 5 and 9
(b) 5 and 7
(c) 4 and 7
(d) 2 and 5
Ans: 5 and 7
Q12. If the distance between a crest and and its consecutive trough is L, then the
wavelength of the wave is given by
(a) L
(b) 2L
(c) 3L
(d) 4L
Ans: 2L
Q13. The reciprocal of frequency is
(a) Wavelength
(b) amplitude
(c) time-period
(d) Wave velocity
Ans: time-period
Q14. Waves formed over water surface are
(a) transverse
(b) longitudinal
(c) both a and b
(d) None of these
Ans: transverse
Q15. The lowest audible frequency for a human being is about
(a) 200 Hz
(b) 20 Hz
(c) 15 Hz
(d) 5 Hz
Ans: 20 Hz
Q16. A tuning fork is vibrating in the air. The number of compressions going past a given point per second
(a) Time-period
(b) Amplitude
(c) Wavelength
(d) Frequency
Ans: Frequency
Q17. The product of time-period and frequency is
(a) Infinitive
(b) Zero
(c) Unity
(d) None of these
Ans: None of these
Q18. When we pluck the wire of a sitar, the waves produced in its wire are :
(a) longitudinal
(b) transverse
(c) both a and b
(d) None of these
Ans: Transverse
Q19. A boat is set into vertical Vibration by waves of speed 5 ms-1 whose crests are
5m apart. The Time period of vertical vibration of the boat is
(a) 4 s
(b) 2 s
(c) 1 s
(d) 0.5 s
Ans: 1 s
Q20. What is the natural of the ocean wave in deep, water
(a) Transverse
(b) Longitudinal
(c) Both a and b
(d) none of these
Ans: Transverse
Q21. Hz is the unit of
(a) Frequency
(b) period
(c) Amplitude
(d) None of these
Ans: Frequency