Physics miscellaneous
- A bottle of sodalime is grasped by the neck and swung briskly in a vertical circle, Near which portion of the bottle do the bubbles collect?
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When the bottle of soda water is grasped by the neck and swung briskly in a vertical circle, the bubbles collect at the top of the bottle which is its neck. What flows in a carbonated drink is carbon dioxide gas. A carbonated beverage forms form bubbles when the dissolved carbon dioxide is depressurized to form emulsions at the top.
Correct Option: C
When the bottle of soda water is grasped by the neck and swung briskly in a vertical circle, the bubbles collect at the top of the bottle which is its neck. What flows in a carbonated drink is carbon dioxide gas. A carbonated beverage forms form bubbles when the dissolved carbon dioxide is depressurized to form emulsions at the top.
- The following particles move with same kinetic energy. Which of them has maximum momentum ?
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The formula for kinetic energy in terms of momentum for fundamental particles is basically just a quantized version of the classical formula,
KE = p2 2m
, where KE is kinetic energy, p is momentum and m is the particle’s mass. In our case, Kinetic energy is constant, therefore p2 = 2m meaning that momentum is directly propor-tional to mass. The mass of particles in ascending order is: alpha, proton and electron. So Alpha particle will have the maximum momentum.Correct Option: D
The formula for kinetic energy in terms of momentum for fundamental particles is basically just a quantized version of the classical formula,
KE = p2 2m
, where KE is kinetic energy, p is momentum and m is the particle’s mass. In our case, Kinetic energy is constant, therefore p2 = 2m meaning that momentum is directly propor-tional to mass. The mass of particles in ascending order is: alpha, proton and electron. So Alpha particle will have the maximum momentum.
- Safety fuse wire used in domestic electrical appliances is made of metal of low
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The fuse wire is based on the Joules law of heating which says that when the electric current is allowed to pass through a conductor, the conductor heats up and is proportional to the square of current. The main object of using fuse wire in electric circuit is to provide protection against short circuit or overload current. For this purpose the material used as fuse wire should have high resistance and low melting point.
Correct Option: B
The fuse wire is based on the Joules law of heating which says that when the electric current is allowed to pass through a conductor, the conductor heats up and is proportional to the square of current. The main object of using fuse wire in electric circuit is to provide protection against short circuit or overload current. For this purpose the material used as fuse wire should have high resistance and low melting point.
- A body absorbs heat most if it is
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A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. Another property is roughness. Sand is rough and black and so it is a good absorber.
Correct Option: A
A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. Another property is roughness. Sand is rough and black and so it is a good absorber.
- The width of depletion layer of a P-N junction
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The total width of the depletion region is a function of applied reverse-bias and impurity concentration. Forward bias decreases the depletion region width whilst reverse bias increases it.
Correct Option: D
The total width of the depletion region is a function of applied reverse-bias and impurity concentration. Forward bias decreases the depletion region width whilst reverse bias increases it.
