1. Mechanics
    2. 1. Units, Dimensions and Errors
    2. Vectors and Scalars
    3. Motion in a Straight Line
    4. Projectile Motion
    5. Newton's Laws of Motion
    6. Friction
    7. Work, Energy, Power and Collision
    8. Circular motion
    9. Rotational motion
    10. Simple Harmonic Motion
    11. Gravitation
    12. Elasticity
    13. Surface Tension
    14. Fluid dynamics and Viscosity
    15. Hydrostatics
  2. Heat and Thermodynamics
    3. 16. Thermometry
    17. Thermal expansion
    18. Calorimetry, Change of State and Hygrometry
    19. Gas Laws and Kinetic theory of Gases
    20. Transmission of Heat
    21. Thermodynamics
  3. Sound and Waves
    4. 22. Wave
    23. Superposition of Waves
    24. Stationary/ Standing waves
    25. Doppler's effect and Musical sound
  4. Optics
    5. 26. Reflection of Plane and Curved Mirrors
    27. Refraction at Plane surfaces and Total internal reflection
    28. Refraction through prism and Dispersion of Light
    29. Refraction through Lenses
    30. Chromatic abberation in Lenses, Optical instruments and Human eye
    31. Velocity of Light
    32. Photometry
    33. Wave nature of Light
  5. Electrostatics
    6. 34. Charge and Force
    35. Electric Field and Potential
    36. Capacitance
  6. Electrodynamics
    7. 37. Electric current
    38. Heating Effect of Current
    39. Thermoelectricity
    40. Chemical effect of Current
    41. Meters
  7. Electromagnetism
    8. 42. Properties of Magnets
    43. Magnetic effects of Current
    44. Electromagnetic induction
    45. Alternating current
  8. Modern Physics
    9. 46. Cathode rays, Positive rays and Electrons
    47. Photoelectric effect
    48. X-rays
    49. Atomic structure and Spectrum
    50. Radioactivity
    51. Nuclear physics
    52. Semiconductor and Semiconductor devices
    53. Diode and Triode valves
    54. Logic gates
    55. Relativity and Universe
    56. Particle physics
Modern Physics
48. X-rays
1. The internal structure of crystal can be studied by
[IOM 2013]

[IOM 2013]

  • X-rays
  • Y-rays
  • IR-rays
  • UV-rays
2. An X-ray tube is operated at 20KV. The maximum speed of electrons striking the anticathode will be
[MOE 2013]

[MOE 2013]

  • 8.4 × 107 m/s
  • 4.2 × 107 m/s
  • 3 × 108 m/s
  • 1.6 × 107 m/s
3. X-rays of wavelength 0.5Å are scattered by a target. What will be the energy of incident X-rays if these are scattered at an angle of 72°
[MOE 2068]

[MOE 2068]

  • 12.41 KeV
  • 6.2 KeV
  • 18.6 KeV
  • 24.82 KeV
4. The shortest wavelength of X-ray in continuous spectrum from an X-ray tube depends on
[MOE 2068]

[MOE 2068]

  • Voltage applied across the tube
  • Current in the tube
  • Nature of gas in the tube
  • Atomic no. of target material
5. An X-ray has a wavelength of 0.01Å. Its momentum in kg.m/s is
[MOE 2010]

[MOE 2010]

  • 6.626 × 10-22
  • 3.313 × 10-22
  • 2.126 × 10-22
  • 3.450 × 10-25
6. Planck's constant is given as 6.6×10-34 Js. The minimum wavelength of X-rays emitted by X-rays tube operating at 30 KV in Å will be nearly
[MOE 2009]

[MOE 2009]

  • 0.4 Å
  • 0.2 Å
  • 0.6 Å
  • 0.8 Å
7. X-rays of wavelength 3Å have frequency of
[KU 2010]

[KU 2010]

  • 1018 Hz
  • 1016 Hz
  • 3×1018 Hz
  • 1020 Hz
8. The minimum wavelength of X-rays can be obtained by
[BP 2010]

[BP 2010]

  • Increasing potential between anode and cathode
  • Increasing filament voltage
  • Increasing intensity of X-rays
  • Changing target material
9. Hydrogen atom cannot produce X-ray because
[BP 2013]

[BP 2013]

  • Its energy levels are too close
  • Its energy levels are too far
  • It is too small
  • It contains only one electron
10. An X-ray tube is operating at 15KV. The lower limit of wavelength of X-rays produced is
[I.E. 2013]

[I.E. 2013]

  • 0.82 × 10-10 m
  • 0.82 × 10-8 m
  • 0.82 × 10-12 m
  • 0.82 × 10-14 m
11. Find out the wavelength from the following figure where energy = 1eV
[I.E. 2013]

[I.E. 2013]

  • 1.24 × 10-6 m
  • 3.33 × 10-7 m
  • 1.24 × 10-7 m
  • 1.33 × 10-6 m
12. A light wave has a frequency of 100Hz. The wavelength of the wave is:
[I.E. 2011]

[I.E. 2011]

  • 3 × 106 m
  • 2 × 106 m
  • 3 × 108 m
  • 2 × 108 m
13. A metal surface has a work function of 4eV. The maximum wavelength of light which can eject the electrons from the surface is
[I.E. 2012]

[I.E. 2012]

  • 310 nm
  • 620 nm
  • 220 nm
  • 155 nm
14. A radio station has a band 30m. The frequency of electromagnetic waves from this station will be
[I.E. 2012]

[I.E. 2012]

  • 10 MHz
  • 3 × 108 Hz
  • 10 KHz
  • 1 × 108 Hz
15. Hardness of X-ray can be increased by increasing:
[BP 2014]

[BP 2014]

  • Voltage between cathode and anode
  • Intensity of light
  • No. of photons of light
  • No. of electrons emitted
16. An X-ray tube operated at 50 KV produces heat at the target at the rate of 740 watt. If 0.5% energy of incident electron is converted into X-rays, then the number of electrons striking the target per second will be
[MOE 2014]

[MOE 2014]

  • 1.1 × 1017
  • 1.1 × 1019
  • 1.1 × 1015
  • 1.1 × 1013
17. If 'h' is Planck's constant, 'c' is velocity of light, 'e' is electronic charge and 'V' is the accelerating potential then maximum wavelength of emitted X-ray photon is given by
[Bangladesh 09]

[Bangladesh 09]

  • hc/eV
  • CV/h
  • h/eV
  • V/e
18. The wavelength of the most energetic X-rays emitted when a metal target is bombarded by 40KV supply is
[MOE 2065]

[MOE 2065]

  • 0.31 Å
  • 300 Å
  • 10 Å
  • 4 Å
19. X-rays are produced by energy change in:
[MOE 2062]

[MOE 2062]

  • Electrons close to the nucleus
  • Electrons far from the nucleus
  • Electrons and proton
  • The nucleus
20. What should be the nature of anticathode in an X-ray tube?
[MOE 2061]

[MOE 2061]

  • High atomic weight, high thermal conductivity
  • High atomic weight, low thermal conductivity
  • Low atomic weight, high thermal conductivity
  • High atomic no., low thermal conductivity
21. The voltage applied to an X-ray is 5000V. What is the minimum wavelength of X-ray produced
[YE-05]

[YE-05]

  • 2.48 × 10-10 m
  • 2.48 × 10-12 m
  • 1.24 × 10-10 m
  • 1.24 × 10-12 m
22. When a beam of accelerated electrons hit a target, a continuous X-ray spectrum is emitted from the target. Which one of the following wavelengths is absent in the X-ray spectrum if the X-ray tube is operated at 40,000 V?
[BPKIHS-07]

[BPKIHS-07]

  • 0.25 Å
  • 0.5 Å
  • 1.0 Å
  • 1.5 Å
23. Hard and Soft X-ray depends on
[BPKIHS-09]

[BPKIHS-09]

  • Wavelength
  • Frequency
  • Velocity
  • Energy
24. X-ray can't penetrate bone because bones have
[BPKIHS-04]

[BPKIHS-04]

  • High molecular wt.
  • Low molecular wt.
  • Hard crystalline structure
  • Amorphous nature
25. The X-ray tube is operated at 50 kV. The minimum wavelength is about
[BPKIHS-06]

[BPKIHS-06]

  • 0.25 Å
  • 0.5 Å
  • 10 Å
  • None
26. In obtaining an X-ray photograph of hand we use principle of
[BPKIHS-94]

[BPKIHS-94]

  • Shadow photography
  • Image formation by an optical system
  • Photoelectric effect
  • Ionisation
27. When cathode rays strike a metal target of high melting point with a very high velocity then which of the following is produced?
  • X-rays
  • α-ray
  • γ-rays
  • UV rays
28. As the potential difference applied to X-ray tube is increased, as a result in the emitted radiation
  • The minimum wavelength decreases
  • The intensity increases
  • The maximum wavelength decreases
  • The minimum wavelength increases
29. A LASER produces
  • A beam of monochromatic coherent light
  • Highly penetrating X-rays
  • A beam of fast moving neutron
  • A beam of monochromatic incoherent light
30. Penetrating power of X-ray can be increased by
  • Increasing P.d between anode and cathode
  • Increasing current in the filament
  • Decreasing the current in the filament
  • Decreasing P.d between cathode and anode
31. The maximum distance between inter-atomic lattice planes is 15 Å. The maximum wavelength of X-rays which are diffracted by the crystal will be
  • 30 Å
  • 15 Å
  • 20 Å
  • 45 Å
32. For which of the following voltage will the wavelength of emitted X-rays will be minimum?
  • 40kV
  • 10kV
  • 20kV
  • 30kV
33. The potential difference between the cathode and anticathode in a Coolidge tube is 120 kV. The maximum frequency of X-rays emitted by it will be
  • 2.9 × 1019 Hz
  • 1.9 × 1018 Hz
  • 2.9 × 1018 Hz
  • 3.9 × 1019 Hz
34. In an X-ray tube, if the electrons are accelerated through 140kV, then anode current obtained is 30mA. If the whole energy of electrons is converted into heat, then the rate of production of heat (in calories/sec) at anode will be
  • 1000
  • 420
  • 1200
  • 640
35. When X-rays of wavelength 1 Å passes through a gold foil of thickness 2.303 mm, then their intensity reduces to half. The coefficient of absorption for gold (in mm-1) will be
  • 0.3
  • 0.2
  • 0.4
  • 0.5
36. An X-ray tube is operated at an accelerating potential of 40kV and the current in the tube is 20mA. Only 2% of the total energy given is converted into X-rays. The maximum energy of emitted radiations will be
  • 6.4 × 10-15 J
  • 1.6 × 10-15 J
  • 4.8 × 10-15 J
  • 3.2 × 10-15 J
37. 50% of X-rays obtained from a Coolidge tube pass through 0.3 mm thick aluminum foil. If the p.d between the target and the cathode is increased, then the fraction of X-rays passing through the same foil will be
  • <50%
  • 50%
  • >50%
  • None of these
38. If the frequency of Kα X-ray emitted from the element with atomic number 31 is ν, then the frequency of Kα X-ray emitted from the element with atomic number 51 would be
  • (51/31)2ν
  • (31/51)ν
  • (51/31)ν
  • (51/31)1/2ν
39. X-rays are:
[KU 2017]

[KU 2017]

  • Electromagnetic radiation of high frequency
  • Positively charged particles
  • Negatively charged particles
  • Neutral particles of low speed