Let lc and lo be the lengths of a closed and the open pipes respectively and v be the velocity of a sound in air. Frequency of a fundamental note of a closed pipe, \(f_c=\frac{v}{4l_c} \) and that of an open .....

At resonance, natural frequency of a body is equal to the frequency of externally applied periodic source. From the principle of superposition, the intensity and hence amplitude of resulting wave is maximum. So, loud sound is heard in this .....

Rubbers are used as vibrations absorbers becasue, in their unstretched state, their molecules are coiled and can be stretched. Thus, during compressing and stretching, a large potential energy can be stored and it elapses slowly. During vibration, .....

It is possible to have a longitudinal wave on a stretched string by stroking it along its length. However, in the wave motion of a stretched string (tant string with fixed ends) wave (disturbance) produced at one fixed end travels along the length .....

The frequency of transverse vibration of a stretched string is given by \(f=\frac{l}{2l}\sqrt{\frac{T}{m}}\), where T is the tension in the string and m is the mass per unit length of the string (=A × .....

The velocity of sound in strings is given by: \(V=\sqrt{\frac{T}{µ}}=\sqrt{\frac{T}{\frac{πd^2}{4}ρ}} \) Since the strings are made up of the same wire and are under the same tension, V ∝ put square root .....

As we know that the frequency of an organ pipe is directly proportional to the velocity of sound in air that is f ∝ v. We have, \(v=\sqrt{\frac{γP}{ρ}} ......(i) \) where P is the pressure, ρ is the .....

When the air in an organ pipe vibrates, the reflection of the sound waves takes place a little above the open end of the pipe. So the length of the air column which has been set into oscillation is not excatly the distance between the two ends of .....

When the stem of vibrating tuning fork is gently passed against the top face of sonometer box, the air enclosed in the box will vibrate. This increases the intensity of sound. The holes in the side of the sonometer box bring the inside air in .....

When the stem of vibrating fork is placed in conatct with a table, a column of air in contact with the table also sets into vibration and resonance occurs due to waves of vibrating fork and such air column. Furthermore, the density of the material .....

f = 250 Hz λ = 8 m ρ = 900 kgm3 We know, v = λf = 8 × 250 = 2000 m/s \(Now,v=\sqrt{\frac{B}{ρ}}[In liquid]\) ∴ v2 × ρ = β or, β = .....

Here, let the velocity of sound be v at 27⁰C. Then v1 = v T1 = (27 + 273) K = 300K Now, the velocity is increased by 50% at temperature T2. \(i.e. v_2=v+\frac{v}{2}=\frac{3v}{2} \) Now, we know that .....

We know, velocity of longitundinal wave (sound) at STP, Vo = 332 m/s Let, V27 be the velocity of sound at 27⁰C We have,  \(V_o=\sqrt{\frac{γP}{ρ}}=\sqrt{\frac{1.4×10^3}{1.29}} \)       = 330 .....

i. Effect of pressure: Velocity of sound in an elastic medium is given by \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)

At night, the atmospheric air becomes more moist than the day time, which reduces the density of air in the night time. As it is know, the velocity of sound is inversely proportional to the square root of density \((i.e. .....

On a cloudy day (humid air), the density of air increases due to the presence of moisture in it. As the velocity of sound is inversely proportional to the square root of the density of air \((i.e. .....

According to Laplace's correction for the velocity of sound, the process of compression and refraction occur so fast that neither heat is transferred nor it is taken from the surrounding. But, the temperature in the different regions does not .....

The velocity of sound in a solid given \(V=\sqrt{\frac{Y}{ρ}} \), where Y is the Young's modulus of the material of the solid and ρ is the density. Although the density of solid is high, the velocity .....

Frequency (f) = 512 Hz Temperature (t) = 17⁰ = 290 K Wavelength (λ) = 66.5 cm = 66.5 × 10-2 m r = ? ρair = 1.293 kgm-3 ρHg = 13600 kgm-3 Since, v = λf ∴ v17 = 66.5 × 10-2 × 512 = .....

Newton's formula for the velocity of sound in a medium (solid, liquid or gas) is given by \(V=\sqrt{\frac{E}{ρ}}......(1) \)        where E = elasticity of medium ρ = density of the .....

The sound is longitudinal wave. In general, the velocity of longitudinal wave is given by \(V=\sqrt{\frac{Y}{ρ}} \), where Y is the modulus of elasticity and ρ is the density of the medium. For the .....

Here, the given equation is y = 0.02 sin(30t - 4x)........(i) We have the equation of standard wave, \(y=a sin(ωt-\frac{2πx}{λ})......(ii) \) Comparing equation (i) with (ii) we get, a) Ampliutde a) = 0.02 m  .....

The principle of superposition of waves states that "If a large number of waves travelling together in the medium, converge to a point, the resulting displacement of any vibrating particel at a given time is equal to the algebric (vector) sum .....

Progressive wave: The wave in which the wave profile travels in forward direction with constant amplitude and frequency is called progressive wave. The wave profile moves along with the speed of the wave. But, when two progressive waves of the same .....

Being a wave, the sound wave undergoes reflection and refraction These phenomena are exhibited by both transverse wave and longitudinal wave. But, the polarization phenomenon is exhibited by transverse wave only. Since the sound wave is longitudinal .....

Given, frequency of sound wave (f) = 800 KHz = 800000 Hz Also, we know velocity of sound in air (v) = 3 × 108 m/s Then, the wavelength of the wave is given by \(λ=\frac{v}{f}=\frac{3×10^8}{800000}=375m .....

When two progressive waves of the same wavelength and amplitude travel with the same speed through a medium in opposite directions, they super impose upon each other and thus a wave is formed which is stationary wave. When a stationary wave is .....

No, we can't hear the cracking sound behind us, if we are walking on the moon surface. This is so because there is no atmosphere on the moon. So there is lack of medium for the propagation of sound waves on the moon. As we know that sound waves .....

The velocity of a wave on travelling through a medium is V = λf. However, when a wave passes from one medium to anotherits velocity changes due to the change in wavelength of the wave but frequency remains the same. Hence the frequency .....

They are: Progressive wave Standing wave The disturbance travels forward and is handed over from one particle to the next after some time. The disturbance is at rest and hence there is no transfer of disturbance to the next .....

If 'd' is the distance between source and reflector then \(t=\frac{d}{v}+\frac{d}{v}=\frac{2d}{v} \) The persistance of vision is 1/10 sec. \(∴\frac{2d}{v}≥\frac{1}{10} .....

T1 = 400 K Q1 = 400 J Q2 = 20 J η = ? T2 = η W = Q1 - Q2 = 400 - 20 = 380 J \(η=(1-\frac{Q_2}{Q_1})×100 \)%      \(=(1-\frac{20}{400})×100 \)%     .....

Here, Mechanical energy (W) = 2200 J Heat discard (Q2) = 4300 J Heat supply (Q1) = ? We know, W = Q1 - Q2 or, Q1 = W + Q2 = 2200 + 4300 = 6500 J       ANS Again, \(Efficiency(η)=(1-\frac{Q_2}{Q_1})×100% .....

η = 30% T2 = 50⁰C T1 = ? We know, \(η=(1-\frac{T_2}{T_1}) \) \(or, \frac{30}{100}=(1-\frac{50}{T_1}) \) \(or, 0.3=\frac{T_1-50}{T_1} \) or, 0.3 .....

Basic difference between first law and second law of thermodynamics: First law of thermodynamics states that, if dQ heat energy is supplied to a body, it increases the internal energy dU and does the work dW. ∴ dQ = dU + dW This means total .....

Carnot's Engine: It consist of i. A heat source maintained at constant high temperature T1K which has infinite capacity. ii. A cold body (called sink) maintained at constant low temperature T2K which has infinite capacity. iii. A perfectly .....

A diesel engine is an internal combustion engine which uses air as working substance and diesel as fuel. It consists of a cylinder provided with three valves namely air inlet valve (I), oil inlet valve (I') and outlet valve (O). These valves are .....

η = 40% = 0.4 T2 = 10⁰C \(∴η=1-\frac{T_2}{T_1}=1-\frac{283}{T_1} \) or, 0.4 T1 = T1 - 283 or, T1 = 471.66 K Second case, η = 65% = 0.65 Let x be the temperature that should be increased. .....

It is the ratio of external work obtained to the heat energy absorbed by the working substance from the source. i.e. η = external work obtained/heat energy absorbed from the source If Q1 be the amount of heat absorbed from the source at .....

Yes, entropy can be defined from the 1st law of thermodynamics. According to 1st law.  dQ = dU + dW or, dQ = pdV     [dU = 0] \(or, dQ=\frac{nRT}{V}dV \)     [∵ pV = nRT] .....

No, a room cannot be cooled by leaving the doors of an electric refrigerator open in a closed room. A refrigerator extracts heat from bodies kept inside it and transfers it to the room and the room gets heated .....

Kelvin temperature scale works on the principle that the pressure of a gas at constant volume increases with temperature.This temperaure scale is indepenedent of the properties of the material. If we plot pressure as a function of temperature, the .....

We know that the efficiency of an internal combustion engine is directly proportional to compressibility. The working substance is compressed about \((\frac{1}{16})^{th} \) of its original volume in a diesel .....

In diesel engines, the working substances (air) can be compressed adiabatically to about \((\frac{1}{16})^{th} \) of its original volume during a compression stroke. The temperature of the working substance .....

The first law explain about internal energy and mechanical work done if certain heat is supplied into a system. It can be applied to know that how much work will be obtained by transforming a certain amount of heat energy. But it fails to explain .....

The first law of thermodynamics tells how heat energy is converted into mechanical work continuously, but it does not indicate why the whole of the energy can not be converted. Also, it does not tell about the condition that heat can be transferred .....

The efficiency of the heat engine is given as \(η=(1-\frac{Q_2}{Q_1}) \) where, Q1 is the heat absorbed from the source and Q2 source is the heat rejected to the sink. Since, Q1 is greater than Q2 (Q1 > Q2). .....

The effectivness of a refrigertaor is measured by the coefficient of performance of the refrigerator. It is the ration of amount of heat absorbed to the workdone in running machine. \(i.e .....

No. of moles, n = 5 Temperature (T) = 53⁰C = 326 K Initial pressure (P1) = 1.00 atm Final pressure (P2) = 3.00 atm Workdone (W) = ? \(W=nRTl_n(\frac{P_1}{P_2}) \)            .....

Initial volume (V1) = V (Say) Initial pressure (P1) = 1.01 × 105 Nm-2 Initail temperature (T1) = 17⁰C = 273 +17 = 290 K Final volume (V2) = \(\frac{V}{8} \) Final temperature (T2) = ? Final .....