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- Question
The energy of a photon, whose momentum is 10 MeV/c, where c is the speed of light, is given by
Options- A. 10 MeV
- B. 100 MeV
- C. 1 MeV
- D. 0.1 MeV
- Correct Answer
- 10 MeV
ExplanationA photon?s relativistic momentum is given by the equation,E = pc where p is the momentum.
P = 10 MeV/c
So, E = 10 MeV
- 1. In total internal reflection, the light travel from
Options- A. rarer to denser medium and it occurs with no loss of intensity
- B. denser to rarer medium and it occurs with no loss of intensity
- C. rarer to denser medium and it occurs with loss of intensity
- D. denser to rarer medium and it occurs with loss of intensity Discuss
- 2. Which one of the following statements is not correct?
Options- A. The response of the ear to sound of increasing intensity is approximately logarithmic.
- B. The sensitivity of the human ear does not vary with the frequency of the sound.
- C. When two or more waves traverse the same medium, the displacement of any element of the medium is the algebraic sum of the displacements due to each wave.
- D. Longitudinal waves can travel in all media-solids, liquids and gases. Discuss
- 3. Which one of the following physical quantities has the same dimensions as that of Planck?s constant h?
Options- A. Linear momentum
- B. Angular momentum
- C. Force
- D. Potential energy Discuss
- 4. The pressure exerted by a 760 mm column of mercury at 0° C is known as
Options- A. 1 pascal
- B. 1 atmosphere
- C. 1 bar
- D. 1 poise Discuss
- 5. In a bipolar junction transistor
Options- A. all the three regions (the emitter, the base and the collector) have equal concentrations of impurity
- B. the emitter has the least concentration of impurity
- C. the collector has the least concentration of impurity
- D. the base has the least concentration of impurity Discuss
- 6. Liquids and gases never show
Options- A. diamagnetic property
- B. paramagnetic property
- C. ferromagnetic property
- D. electromagnetic property Discuss
- 7. Light travels in a straight line (rectilinear propagation of light). This statement does hold if the medium of travel for light is
Options- A. of variable refractive index
- B. made up of slabs of different refractive indices
- C. homogeneous and transparent
- D. inhomogeneous and transparent Discuss
- 8. Two identical solid pieces, one of gold and other of silver, when immersed completely in water exhibit equal weights. When weighed in air (given that density of gold is greater than that of silver)
Options- A. the gold piece will weigh more
- B. the silver piece will weighmore
- C. both silver and gold pieces weigh equal
- D. weighing will depend on their masses Discuss
- 9. If the wavelengths corresponding to ultraviolet, visible and infrared radiations are given as lUV, lVIS and lIR respectively, then which of the following gives the correct relationship among these wavelengths?
Options- A. lUV < lIR < lVIS
- B. lUV > lVIS > lIR
- C. lUV > lIR > lVIS
- D. lUV < lVIS < lIR Discuss
- 10. An electron and a proton starting from rest get accelerated through potential difference of 100kV. The final speeds of the electron and the proton are Ve and Vp respectively. Which of the following relations is correct?
Options- A. Ve > Vp
- B. Ve < Vp
- C. Ve = Vp
- D. Cannot be determined Discuss
Physics problems
Search Results
Correct Answer: denser to rarer medium and it occurs with no loss of intensity
Explanation:
According to wave theories, for Total internal reflection tohappen: Light must travel from denser medium to rarer medium. Angle of incidence should be greater than critical angle. As in case of TIR, the image is perfectly clear, it implies that there has been no loss of intensity.
Correct Answer: The sensitivity of the human ear does not vary with the frequency of the sound.
Explanation:
The human ear can respond to minute pressure variations inthe air if they are in the audible frequency range, roughly 20 Hz -20 kHz. In fact, tests conducted show an increased sensitivity in the 3000 Hz range which is the optimal amplification frequency in the human ear. So, the sensitivity of the human ear varies with the frequency of the sound.
Correct Answer: Angular momentum
Explanation:
In S.I. System unit of angular momentum is "joule.Second".
SI unit of Planck's constant is joule-seconds(j-s).
Correct Answer: 1 atmosphere
Explanation:
1 atm: It was originally defined as the pressure exerted by 760 mm of mercury at 0 °C and standard gravity (g = 9.80665 m/s2).
Correct Answer: the base has the least concentration of impurity
Explanation:
In terms of concentration of impurity (a.k.a impurity doping concentration, often abbreviated to doping concentration), from the highest to the lowest among the three regions of a bipolar junction, emitter, collector, and base are the correct order. The above order is independent of the type of BJT, npn or pnp
Correct Answer: ferromagnetic property
Explanation:
On the basis of magnetic properties, substances are classified into three groups namely diamagnetic, paramagnetic and ferromagnetic.
As solids diffuse and reorder very slowly under ambient conditions, the net, directionally dependent (anisotropic) magnetic moment can persist. Conversely, liquids and gases freely tumble and reorder: water rearranges every few pico seconds (10^12 times per second).
Hence liquids and gases can never show ferromagnetic properties.
Correct Answer: homogeneous and transparent
Explanation:
In vacuum and in homogeneous, transparent media, such as air, water, and glass, light moves in a straight line. When light encounters a boundary between two different transparent media, some light is reflected and some moves from the first into the second medium.
Correct Answer: the silver piece will weighmore
Explanation:
As it is said that density of gold is greater than that of density of silver, so silver occupies a greater volume than gold. So it has more upthrust from the water, although they both show the same weight under water, there is more silver present. Hence silver piece will weigh more.
Correct Answer: lUV < lVIS < lIR
Explanation:
Infrared radiation, what we experience as heat when we hold our hand near a warm object, is somewhat longer wavelengths than visible light. Visible light is simply electromagnetic radiation in a range of wavelengths that our eyes are sensitive to. Visible wavelengths range from 0.0007 milimeters for red light, through orange, yellow, green, and blue, to 0.0004 milimeters for violet light. Ultraviolet is shorter wavelengths than violet.
Longer the wavelength,lower the energy
Correct Answer: Ve > Vp
Explanation:
Both when accelerated through a potential difference of 100KV, they will have the same energy. The mass of the electron is less than the mass of a proton, hence it will move faster(momentum).
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