# RRB JE Exam: Physics (Sound) Quiz | 4th March

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Q1.The Doppler’s effect is applicable for
डॉपलर का प्रभाव किस पर लागू होता है?
(a) light wave/ प्रकाश तरंग
(b) sound wave/ ध्वनि तरंग
(c) space wave/ अंतरिक्ष तरंग
(d) both (a) and (b)/(a) और (b) दोनों

S1.Ans(d)
Sol. The Doppler effect can be observed to occur with all types of waves – most notably water waves, sound waves, and light waves. That was the Doppler effect – a shift in the apparent frequency for a sound wave produced by a moving source.

Q2.If a sound travels from air to water, the quantity that remain unchanged is

यदि कोई ध्वनि हवा से पानी तक जाती है, तो वह मात्रा जो अपरिवर्तित रहती है, वह
(a) velocity/ वेग
(b) frequency/ आवृत्ति
(c) wavelength/ तरंग दैर्ध्य
(d) amplitude/ आयाम

S2.Ans(b)
Sol. If a sound travels from air to water, the quantity that remain unchanged is frequency.

Q3.Waves which do not require any material medium for its propagation is–

तरंगे जिनके प्रसार के लिए किसी भी भौतिक माध्यम की आवश्यकता नहीं होती है-
(a) Matter waves/ द्रव्य तरंगें
(b) Mechanical waves/ यांत्रिक तरंगें
(c) Elastic waves/ लोचदार लहरें
(d) Electromagnetic waves/ विद्युतचुम्बकीय तरंगें

S3.Ans(d)
Sol. Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.

Q4.Sound travels fastest in
ध्वनि सबसे तेज किस में यात्रा करती हैं?
(a) steel /स्टील
(b) air /हवा
(c) water /पानी
(d) vacuum /वेक्यूम

S4.Ans(a)
Sol. The speed of sound depends on the medium in which it is transported. Sound travels fastest through solids, slower through liquids and slowest through gases.

Q5.Beats occur because of

बीट्स किस की वजह से होती हैं?
(a) interference/ हस्तक्षेप
(b) reflection/ प्रतिबिंब
(c) refraction/ अपवर्तन
(d) doppler effect/ डॉपलर प्रभाव

S5.Ans(a)
Sol. A beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies.

Q6.The types of waves produced in a sonometer wire are
सोनोमीटर तार में पैदा होने वाली तरंगें किस प्रकार की होती हैं?
(a) longitudinal stationary/ अनुदैर्ध्य स्थिर
(b) transverse stationary/ अनुप्रस्थ स्थिर
(c) longitudinal progressive/ अनुदैर्ध्य प्रगतिशील
(d) None of these/इनमें से कोई नहीं

S6.Ans(b)
Sol. If the vibrations of the particles are perpendicular to the propagation of the wave, those waves are said to be transverse waves. Waves produced in a sonometer wire is transverse stationary wave.

Q7.With the increase in temperature, the frequency of the sound from an organ pipe

तापमान में वृद्धि के साथ, एक अंग पाइप से ध्वनि की आवृत्ति ___________ होती है.
(a) decreases/घटती है
(b) increases/बढती है
(c) remain unchanged/समान रहती है
(d) changes erractically/ अनिश्चित रूप से बदलती है

S7.Ans(c)
Sol. Temperature doesn’t affect the frequency of sound waves, but affects the speed of sound in the air.

Q8.The phenomenon in which the amplitude of oscillation of pendulum decreases gradually is called
वह घटना जिसमें पेंडुलम के परिसंचरण का आयाम धीरे-धीरे कम हो जाता है क्या कहलाता है?
(a) decay period of oscillation/ परिसंचरण की क्षय अवधि
(b) damping/ डेम्पिंग
(c) building up oscillation/ परिसंचरण का निर्माण
(d) maintained oscillation/ परिसंचरण बनाए रखा

S8.Ans(b)
Sol. Damping is any effect that tends to reduce the amplitude of vibrations. In mechanics, the internal friction may be one of the causes of such damping effect.

Q9.When two sound waves are superimposed, beats are produced when they have

जब दो ध्वनि तरंगों को अध्यारोपित किया जाता है, तो बीट्स उत्पन्न होती हैं जब उनके पास _________ होता है
(a) different amplitudes and phases/ विभिन्न आयाम और चरण
(b) different velocities/ विभिन्न वेग
(c) different phases/ विभिन्न चरण
(d) different frequencies/ विभिन्न आवृत्ति

S9.Ans(d)
Sol. When two sound waves are superimposed, beats are produced when they have different frequencies.

Q10.Out of the following, which frequency is not clearly audible to the human ear?

निम्नलिखित में से, कौन सी आवृत्ति स्पष्ट रूप से मानव कान के लिए श्रव्य नहीं है?
(a) 30 Hz
(b) 30,000 Hz
(c) 300 Hz
(d) 3000 Hz