Physics Questions and Answers

The Bohr model is a model of the atom that describes electrons as orbiting the nucleus in specific energy levels. This model was developed by Niels Bohr in 1913 and it is based on the work of Max Planck and Albert Einstein. The Rutherford model, the Thomson model, and the Dalton model are all older models of the atom that are not as accurate as the Bohr model.

Surface tension is the force that acts on the surface of a liquid, tending to minimize the surface area. It is caused by the cohesive forces between the molecules of the liquid. The stronger the cohesive forces, the higher the surface tension.

Mercury has the highest surface tension of all the liquids listed. This is because the atoms of mercury are very close together, and they have a strong attraction for each other. This strong cohesive force results in a high surface tension.

Instrument resolution is not a limitation of experimental measurements. It is the smallest change in a measured quantity that can be detected by an instrument. While instrument resolution limits the accuracy of a measurement, it is not a limitation of experimental measurements itself.

The stopping potential is the voltage that is required to stop the emitted photoelectrons from reaching the anode. When the frequency of the light is increased, the kinetic energy of the emitted photoelectrons also increases. This means that a higher stopping potential will be required to stop the photoelectrons from reaching the anode

\(V_L\)=60 V ,\(V_C\) = 120 V ,  \(V_R\) =30V
 

;V = ?

; \(V^2\) = \(V_R^2\) +  \(V_L\) -  \(V_C^2\)

= \(V^2\) = \(30^2\)  + \(60 - 120^2\)

= \(V^2\)  = 900 + 3600

= \(V^2\)  = 4500

=  V =  √4500 = 67V

An incandescent light source is a type of light source that produces light by heating a material until it glows. The material that is heated is usually a metal, such as tungsten. Fluorescent lamps, LED lamps, and neon lamps are all examples of non-incandescent light sources.

Fluorescent lamps produce light by passing an electric current through a gas, which causes the gas to emit ultraviolet light. The ultraviolet light then causes a coating on the inside of the lamp to fluoresce, which produces visible light.

LED lamps produce light by passing an electric current through a semiconductor material, which causes the material to emit photons. The photons then produce visible light.

Neon lamps produce light by passing an electric current through a gas, which causes the gas to emit visible light.

The working of the beam balance is based on the principle of moments. The principle of moments states that the sum of the clockwise moments on a beam must be equal to the sum of the counterclockwise moments on the beam. This means that the weight of the object on the left side of the beam must be multiplied by the distance from the fulcrum to the left side of the beam, and the weight of the object on the right side of the beam must be multiplied by the distance from the fulcrum to the right side of the beam. If these two products are equal, then the beam will be in equilibrium.

Mechanics is the branch of physics that deals with the motion of objects and the forces acting on them. It is the foundation of all other branches of physics, and it is used to study everything from the motion of planets to the motion of electrons.

q=\(4.6 × 10^{-5}\), C=   \(3.2 × 10^4\) \(Vm^{-1}\) F= ?

F=qE

⇒ \(4.6 × 10^{-5}\)C × \(3.2 × 10^4\)

; F= 1.5 N

d=312m.,T =263\(-10^°c\) = -10+273K = 263K, t=?

v= 331√ \(\frac{T}{273}\)

⇒ v = 331×√ \(\frac{263}{273}\)

⇒ v = 324.88 \(ms^-1\)

⇒ v = \(\frac{d}{t}\)

t = \(\frac{d}{t}\) = \(\frac {312}{324.88}\)

t = 0.96s