The figure shows a glass container filled with air and having an electric bell kept inside it. A person standing close to it can distinctly hear the bell. Now the air inside is removed slowly.

Will the person be able to hear the bell after the air in the container is completely removed? Why?

The figure shows a glass container filled with air and having an electric bell kept inside it. A person standing close to it can distinctly hear the bell. Now the air inside is removed slowly. How does the speed of sound get affected when there is an increase of moisture in the air?

A beaker containing a liquid is kept inside a big closed jar. If the air inside the jar is continuously pumped out, the pressure in the liquid near the bottom of the liquid will

A person standing between two vertical cliffs and 640 m away from the nearest cliff, produces sound. He hears the first echo after 4 s and the second echo 3 s later. Calculate : the speed of sound in air,

Air filled capacitor is charged by a battery and after charging battery is removed. A slab of dielectric material is inserted in it to fill the space completely . The electric field in the capacitor is

An object O is kept in air and a lens of focal length 10 cm (in air) is kept at the botton of a container which is filled upto a height 44 cm by water. The refractive index of water is 4//3 and that of glass is 3//2 . The botton of the container is closed by a thin glass slab of refractive index 3//2 . Find the distance (in cm ) of the final image formed by the system from botton of container (refer to figure shown below).

In given figure, A uniform cylindrical tube closed at one end, contains a pallet of mercury 5cm long. When the tube is kept verticaly with the closed end downward, the length of the air column trapped is 30cm . Now the tube is inverted so that the closed end goes up find the new length of the air column trapped. atmospheric pressure =75cm of mercury. (Assume temperature remains constant in this process)

Two parallel plate capacitors A and B have the same separation d=8.85xx10^-4m between the plates. The plate area of A and B are 0.04m^2 and 0.02m^2 respectively. A slab of dielectric constant (relative permittivity) K=9 has dimensions such that it can exactly fill the space between the plates of capacitor B. (i) The dielectric slab is placed inside. A as shown in figure (a). A is then charged to a potential difference of 110V. Calculate the capacitance of A and the energy stored in it. The battery is disconnected and then the dielectric slab is moved from A. Find the work done by the external agency in removing the slab from A. (iii) The same dielectric slab is now placed inside B, filling it completely, The two capacitors A and B are then connected as shown in figure(c). Calculate the energy stored in the system.

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. This person (without hearing aid machine) is sitting inside a busy restaurant where average sound intensity is 3.2xx10^-5(W)/(m^2) . How much energy in the form of sound is taken up by the person in his meal time of 1 h?

Figure shows water in a container having 2.0-mm thick walls made of a material of thermal conductivity 0.50Wm^(-1)C^(-1) . The container is kept in a melting-ice bath at 0^(@)C . The total surface area in contact with water is 0.05m^(2) . A wheel is clamped inside the water and is coupled to a block of mass M as shown in the figure. As the goes down, the wheel rotates. It is found that after some time a steady state is reached in which the block goes down with a constant speed of 10cms^(-1) and the temperature of the water remains constant at 1.0^(@)C .Find the mass M of the block. Assume that the heat flow out of the water only through the walls in contact. Take g=10ms^(-2) .

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. If the person is using an hearing aid, which increase the sound intensity level by 30 dB, then by what factor the intensity of given sound wave change as perceived by inner ear?