How does an electric heater work? Answer: Electric heaters are one of the devices that work by using the thermal effect of electric current. Electric heaters can withstand high temperatures and consist of coils of nichrome wire placed in circular grooves on discs made of non-conductive mica or fire clay. When the two ends of […]
Why the sound of the sun does not reach the earth? The light from the sun or the moon reaches the earth, but the sound does not. Since light is an electromagnetic wave, no inert medium is absolutely necessary for the propagation of light. Light can also travel through a vacuum. So even though most
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How does an electric iron work? Answer: An electric iron is one of the devices that work by using the thermal effect of electric current. In electric irons, coils of nichrome wire are wound over a triangular structure of mica. The coil is wrapped with two sheets of mica for insulation. It is kept in
Why does the filament of a light bulb glow but the connecting wires do not? Answer: Two wires do not emit light even though the same current flows in the two thick wires connecting the filaments in the electric lamp. Thick wires connecting the filaments have shorter lengths and relatively larger cross-sections. So their resistance
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Answer: The buzzing sound of a mosquito is sharper than the roar of a tiger because the frequency of the sound produced by the vibration of the mosquito’s wings is much higher than the frequency of the tiger’s roar.
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Why is the voice of children and women sharper than the voice of men? Answer: Children’s and women’s voices are sharper than men’s voices. The human throat has two membranes called vocal cords. As a result of their vibration, the sound comes out of the throat. Male vocal cords become stronger with age. As a
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Why does the sound of water change as a bucket is filling from empty to full? If you keep an empty bucket under the faucet and fill it with water, you can hear a loud sound at first, but the sound gets louder as the bucket fills up. Answer: When an empty bucket is placed
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The sound of the distant train can be heard on the line, but if you take your ear off the line, why can’t the sound be heard? Answer: If you listen to the railway line, you can hear the sound of distant trains. But if you take your ear off the line, you can no
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Why can’t we hear sound in water? Answer: If you make a sound in the water, the sound cannot be heard outside the water. Because, if the density difference between the two mediums is large, sound does not propagate easily from one medium to the other. Because water is denser than air, the sound inside
Why can’t we hear sound in water? Answer: A person submerged in water cannot hear any sound outside the water. Because water is denser than air, sound cannot propagate from air to water. As a result, a person submerged in water cannot hear any sound outside the water.
