Description : The X-rays emitted in inner shell transitions are called _____ as their energy depends upon the type of target material. a) gamma rays b) special X-rays c) Characteristic X-rays d) continuous X-rays
Last Answer : c) Characteristic X-rays
Description : Molecules of a solid possess a) Rotational motion b) Vibrational motion c) Translational motion d) All of above
Last Answer : b) Vibrational motion
Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays
Last Answer : b) X-rays
Description : When cathode rays strike a target of high atomic weight, they give rise to – 1) α -rays (2) β and γ rays (3) X-rays (4) positive rays
Last Answer : (3) X-rays Explanation: When cathode rays strike a solid target of high atomic weight and high melting point such as tungsten, molybdenum, etc, they give rise to a highly pen-etrating radiation called the X-rays (LIT Physics by Dr. P.K Aganval).
Description : The reverse process of photo-electric effect is called: a) Annihilation of matter b) Compton effect c) Pair production d) X-rays
Last Answer : d) X-rays
Description : Pair production can be studied with a) Ultraviolet rays b) X-rays c) Microwaves d) -rays
Last Answer : d) -rays
Description : Which one of the following phenomena can be studied with -rays a) Photoelectric effect b) Compton effect c) Pair production d) All of the above
Last Answer : a) Photoelectric effect
Description : Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer cannot take place (A) Between two bodies in physical contact ... of a body to the another part of the same body (D) Both 'b' & 'c'
Last Answer : (B) Between two bodies not in physical contact with each other
Description : The beam that leaves the target is called, A. The primary X-ray B. The electrons ( from the cathode) C. The secondary rays (scattered radiation) D. X-ray photons no
Last Answer : A. The primary X-ray
Description : A substance emits energy which is detected as a line emission in the visible region using a spectroscope. The origin of this energy is (a) Vibrational energy of the molecules (b) Rotational energy of the molecules (c) Energy of orbital electrons (d) Energy of protons in the nucleus.
Last Answer : Ans:(c)
Description : X-rays that are emitted in all directions and with a continuous range of frequencies are known as a) characteristic X-rays b) continuous X-rays c) scattered X-rays d) stimulated X-rays.
Last Answer : b) continuous X-rays
Description : X-rays were discovered by: a) Roentgen b) Becquerel c) Marie Curie d) Van Lave
Last Answer : a) Roentgen
Description : In human flesh, the three light elements which predominate, and allow greater amount of incident X-rays to pass through them are a) oxygen, nitrogen , hydrogen b) oxygen, hydrogen, helium c) oxygen, hydrogen, carbon d) carbon, nitrogen, oxygen
Last Answer : c) oxygen, hydrogen, carbon
Description : X-rays can penetrate several ____ into a solid matter. a) millimeters b) meters c) centimeters d) kilometers
Last Answer : c) centimeters
Description : Which one of the following radiations has the most energetic photon? a) T.V. waves b) Micro waves c) X-rays d) - rays
Last Answer : d) - rays
Description : Which one of the following waves requires a material medium for their propagation? a) Light waves b) X– rays c) -rays d) Sound waves
Last Answer : d) Sound waves
Description : The practical application of electrostatic is: (a) Photocopier (b) X-rays machines (c) Laser (d) All of above 42. The electric field lines emerge from the charges in: (a) Three dimensions (b) Two dimensions (c) One dimension (d) All of above
Last Answer : (a) Photocopier
Description : Free electrons are: (a) Fixed (b) Loosely bounded (c) Strongly fixed (d) Tightly bound
Last Answer : (b) Loosely bounded
Description : Metals are good conductors of electricity because they have: (a) Large number of bounded electrons (b) Small number of electrons (c) Large number of free electrons (d) Small number of free electrons
Last Answer : (c) Large number of free electrons
Description : ___________ remain undeflected in a magnetic field a) β particles b) α particles c) γ rays d) Proton beams
Last Answer : c) γ rays
Description : According to Bohr’s theory, the fourth stationary orbit of electrons in the hydrogen atom is a) 4 (0.053 nm) b) 9 (0.053 nm) c) 16 (0.053 nm) d) 25(0.053 nm)
Last Answer : c) 16 (0.053 nm)
Description : The minimum frequency required to eject electrons from a metallic surface is called a) Critical frequency b) Peak value of frequency c) Threshold frequency d)Photo frequency
Last Answer : c) Threshold frequency
Description : The reverse current through semiconductor diode is due to (a) Minority carrier (b) majority carrier (c) electrons (d) holes
Last Answer : (a) Minority carrier
Description : Forward current through a semi-conductor diode circuit is due to ________ (a) Minority carriers (b) majority carriers (c) holes (d) electrons
Last Answer : (b) majority carriers
Description : N-type region has majority charge carriers as (a) Holes (b) protons (c) neutrons (d) electrons
Last Answer : (d) electrons
Description : Minority carriers in N-type are a) Holes b) Electrons c) Neutrons d) Protons
Last Answer : a) Holes
Description : The majority carriers in N-type substance are a) Holes b) Protons c) Neutrons d) Electrons
Last Answer : d) Electrons
Description : The electrons in the outermost orbit of atom are: a) Valance electrons b) Static electrons c) Tightly bound d) Stationary
Last Answer : a) Valance electrons
Description : The electrostatic force of repulsion between two electrons at 1 metre is: (a) 9 × 109 N (b) 1.44 × 10−9 N (c) 2.30 × 10−28 N (d) 1 N
Last Answer : (c) 2.30 × 10−28 N
Description : The number of electrons in one coulomb charge is equal to: (a) 6.2 × 1018 electrons (b) Zero electrons (c) 1.6 × 10−22 electrons (d) 6.2 × 1021 electrons
Last Answer : (a) 6.2 × 1018 electrons
Description : Primary cosmic rays are composed largely of very fast-----? A. Protons (Answer) B. Neutrons C. Electrons D. Gamma rays
Last Answer : A. Protons (Answer)
Description : Moving coil in dynamometer wattmeter connected a) In series with fixed coil b) Across supply c) In series with load d) Across load
Last Answer : Ans: Across supply
Description : A magnetic field exists around (a) iron (b) copper (c) aluminium (d) moving charges
Last Answer : (d) moving charges
Description : The wavelength of the wave associated with the moving object is a) Directly proportional to the accelerating voltage b) Directly proportional to the square of accelerating voltage c) ... proportional to the square root of accelerating voltage d) Inversely proportional to the accelerating voltage
Last Answer : c) Inversely proportional to the square root of accelerating voltage
Description : The induced current can be increased by: a. Using strong magnetic field b. moving loop faster c. Replacing loop by coil d. all of above
Last Answer : d. all of above
Description : If velocity of a conductor moving through a magnetic field ‘B’ is made zero, then Motional emf will be: a. –VBL b. –V/BL c. – BL/V d. zero
Last Answer : a. –VBL
Description : A proton and a deuteron have same kinetic energies while moving in a perpendicular magnetic field. The following gives the ratio of radii of their circular paths a) √2 : 1 b) 1: √2 c) 1:4 d) 1:1
Last Answer : b) 1: √2
Description : Work done by a uniform magnetic field in moving a charged particle in a circular path is a) qvB sin θ b) mg sin θ c) zero d) mg cos θ
Last Answer : Zero
Description : The pole faces of U-shaped magnet in a moving coil galvanometer are made concave to a) decrease the strength of magnetic field b) create a non-uniform magnetic field c) make the magnetic field radial d) All of these
Last Answer : c) make the magnetic field radial
Description : ___________ is not affected by a magnetic field a) Change in magnetic flux b) a moving electron c) a stationary proton d) current flowing in a conductor
Last Answer : c) a stationary proton
Description : In a springy collision, if the fast moving trolley collides with a slow one, then the fast one will bounce back at speed of A. slow one B. less than slow one C. more than slow one D. with the same speed as before
Last Answer : slow one
Description : rays of light strike a horizontal plane mirror at an angle of `45^(@)`. At what angle should be a second plane mirror be placed in order that the refl
Last Answer : rays of light strike a horizontal plane mirror at an angle of `45^(@)`. At what ... ray finally be reflected horizontally from the second mirror.
Description : What happens when cathode rays strike the glass walls of the cathode ray tube?
Last Answer : Feel Free to Answer
Description : When do the suns rays strike 23.5 at an angle of Y degrees?
Last Answer : Need answer
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber. ∙ A. Acceptance cone half-angle ∙ B. Acceptance cone ∙ C. Critical angle ∙ D. Angle of incidence
Last Answer : A. Acceptance cone half-angle
Description : The maximum angle in which external light rays may strike the air/glass interface and still propagate down the fiber.
Last Answer : Acceptance cone half-angle
Description : The Beta particles are fast moving------? A. Protons B. Electrons (Answer) C. Neutrons D. None
Last Answer : B. Electrons (Answer)
Description : X-rays are produced by impinging_______on a target.
Last Answer : X-rays are produced by impinging_______on a target. A. `alpha` particles B. protons C. electrons D. neutrons
Description : In the phenomenon of Laser production, atom can reside in the meta stable state for a) ~ 10-3 s b) ~ 10-8 s c) ~ 10-4 s d) ~ 10-10 s
Last Answer : a) ~ 10-3 s
Description : In the phenomenon of Laser production, atom can reside in the excited state only for a) 10-6 s b) 10-7 s c) 10-8 s d) 10-9 s
Last Answer : c) 10-8 s