Physics M.C.Q (1 Marks)

A proton, a deutron and an a-particle having the same momentum, enters a region of uniform electric field between the parallel plates of a capacitor. The electric field is perpendicular to the initial path of the particles. Then the ratio of deflections suffered by them is

The work function of a metal is 1.6  J. When the metal surface is illuminated by the light of wavelength  6400 Å, then the maximum kinetic energy of emitted photo-electrons will be (Planck's constant h = 6.4 )

The ratio of de-Broglie wavelength of a a-particle to that of a proton being subjected to the same magnetic field so that the radii of their path are equal to each other assuming the field induction vector   is perpendicular to the velocity vectors of the a-particle and the proton is

The energy of a photon of wavelength  is given by

In a dark room of photography, generally red light is used. The reason is

The electrons are emitted in the photoelectric effect from a metal surface         

The stopping potential (  versus frequency (n) plot of a substance is shown in figure the threshold wave length is

Assertion :   The threshold frequency of photoelectric effect supports the particle nature of sunlight.

Reason      : If frequency of incident light is less than the threshold frequency, electrons are not emitted from metal surface.

Assertion   :   Photoelectric effect demonstrates the wave nature of light.

Reason       : The number of photoelectrons is proportional to the frequency of light.

The wavelength of de-Broglie wave is 2mm, then its momentum is (h = 6.63 × 10^–34 J-s)

Which of the following statements is correct

When a point source of monochromatic light is at a distance of 0.2 m from a photoelectric cell, the cut-off voltage and the saturation current are 0.6 volt and 18 mA respectively. If the same source is placed 0.6 m away from the photoelectric cell, then

If a photon has velocity c and frequency n, then which of following represents its wavelength

Stopping potential for photoelectrons

The minimum wavelength of the X-rays produced by electrons accelerated through a potential difference of V volts is directly proportional to

(a)

(b)

(c) 1/

(d) 1/V

An electron beam in an X-ray tube is accelerated through a potential difference of 50000 volts. These are then made to fall on a tungsten target. The shortest wavelength of the X-ray emitted by the tube is

The largest distance between the interatomic planes of a crystal is 10^-7cm. The upper limit for the wavelength of X-rays which can be usefully studied with this crystal is

The energy of a photon of characteristic X-rays from  a Coolidge tube comes from

The wavelength of  X-rays produced by an X-ray tube is 0.76 Å. The atomic number of the anode material of the tube is

In an X-rays tube, the intensity of the emitted X-rays beam is increased by

The structure of solid crystals is investigated by using

X-rays region lies between

X-rays are produced due to

X-rays of which of the following wavelengths are hardest

X-rays are known to be electromagnetic radiations. Therefore the X-ray photon has

Which of the following is accompanied by the characteristic X-ray emission         

 characteristic X-ray refers to the transition

The continuous X-rays spectrum produced by an X-ray machine at constant voltage has

The X-ray beam coming from an X-ray tube will be

X-rays are not used for radar purpose because

When a beam of accelerated electrons hits a target, a continuous X-ray spectrum is emitted from the target. Which of the following wavelength is absent in the X-ray spectrum, if the X-ray tube is operating at 40,000 volts

X-rays are in nature similar to

Compton effect is associated with

Molybdenum is used as a target element for production of X-rays because it is

The voltage applied across an X-rays tube is nearly

X-rays are

X-rays were discovered by

The minimum wavelength of X-rays produced by electrons accelerated by a potential difference of volts is equal to

(a)

(b)

(c)

(d)

Hydrogen atom does not emit X-rays because

In  radio theraphy, X-rays are used to

When the accelerating voltage applied on the electrons increased beyond a critical value

The wavelength   of the   line of characteristic X-ray spectra varies with atomic number approximately

(a)

(b)

(c)

(d)

An X-ray tube is operated at 50 kV. The minimum wavelength produced is

The characteristic X-ray radiation is emitted, when

Einstein got Nobel prize on which of the following works

The mass of the electron varies with

X-rays of wavelength 0.1 Å allowed to fall on a metal get scattered. The wavelength of scattered radiation is 0.111 Å. If h = 6.624 × 10^–34 J-s and m₀ = 9 × 10^–31 kg, then the direction of the scattered photons will be

The continuous x-ray spectrum obtained from a Coolidge tube is of the form

The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve

Figure represents the graph of photo current I versus applied voltage (V). The maximum energy of the emitted photoelectrons is