Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
Bohr model
Dalton model
Rutherford model
Thomson model
Correct answer is A
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.
Which of the following liquids has the highest surface tension?
Soapy water
Water
Mercury
Oil
Correct answer is C
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.
Which of the following is NOT a limitation of experimental measurements?
Systematic error
Instrument resolution
Random errors
Human error
Correct answer is B
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 does not change.
The stopping potential decreases.
The stopping potential can either increase or decrease, depending on the intensity of the light
The stopping potential increases.
Correct answer is D
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
81
67
59
73
Correct answer is B
\(V_L\)=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