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 : The incident photon absorbed by an atom in the ground state E1, thereby leaving the atom in the excited state E2 , is a) spontaneous absorption b) stimulated absorption c) induced absorption d) both b & c
Last Answer : d) both b & c
Description : Red Laser light has a wavelength of a) 630.8 nm b) 630 cm c) 632.8 nm d) 639.9 nm
Last Answer : c) 632.8 nm
Description : An atomic energy state in which more atoms are in the lower energy state E1 than in the excited state E2, is known as a) population inversion b) normal population c) stimulated population d) atomic population
Last Answer : b) normal population
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 : Whichofthe followingantennasis best excited fromawaveguide? a. Biconical b.Horn c. Helical d. Discone
Last Answer : b.Horn
Description : The energy required to completely remove an electron from the first Bohr orbit is called a) excited energy b) ionization energy c) accelerated energy d) orbital energy
Last Answer : b) ionization energy
Description : In order to obtain spectrum from the emitted radiation, the atomic gas or vapour must be excited at a) much less than atmospheric pressure b) much high than atmospheric pressure c) atmospheric pressure d) high pressure and temperature
Last Answer : a) much less than atmospheric pressure
Description : In Helium-neon Laser, in meta stable state, helium is located at the energy level: a) 20.66 eV b) 20.77 eV c) 20.61 eV d) 20.71 eV
Last Answer : c) 20.61 eV
Description : The phenomenon of producing emf in the coil due to change of current in the coil itself is called: a. mutual induction b. self-induction c. self-inductance d. mutual inductance
Last Answer : d. mutual inductance
Description : The radius of hydrogen atom is about a) 5 x 10-11 m b) 5 x 10-11 cm c) 5 x 10-11 mm d) 5 x 10-11 dm
Last Answer : a) 5 x 10-11 m
Description : Laser is the acronym for a) Light Amplification by Stimulated Emission of Radiation b) Light Amplification by Spontaneous Emission of Radiation c) Light Amplified by Stimulated Emission of Radiation d) Light Amplification by Standard Emission of Radiation
Last Answer : a) Light Amplification by Stimulated Emission of Radiation
Description : Laser technology has been widely used in the field of a) neurology b) astrology c) ophthalmology d) psychology
Last Answer : c) ophthalmology
Description : Laser beams can generate three dimensional images of objects in a process called a) polygraphy b) telegraphy c) holography d) autography
Last Answer : c) holography
Description : In Helium-neon Laser discharge tube, neon gas is a) 85% b) 15% c) 75% d) 45%
Last Answer : b) 15%
Description : In Helium-neon Laser discharge tube, helium gas is a) 15% b) 85% c) 75% d) 35%
Last Answer : b) 85%
Description : Common type of Laser used in physics laboratories is a) hydrogen neon Laser b) helium-neon Laser c) carbon neon Laser d) argon neon laser
Last Answer : b) helium-neon Laser
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 : Good conductors have conductivity of the order of a) 10–10 (m)–1 b) 10–7 (m)–1 c) 10 7 (m)–1 d) 10–9 (m)–1
Last Answer : c) 10 7 (m)–1
Description : The minimum charge on any electron be less than: (a) 1.6×10−19C (b) 3.2×10−19C (c) 1.8×10−19C (d) 9.1×10−19C
Last Answer : (a) 1.6×10−19C
Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV
Last Answer : b) 1.02 MeV
Description : A current of 5.8 A flows through a 0.25 m long straight conductor which is kept perpendicular in a region of uniform magnetic field of 3.7 T . The force on conductor is a) 5.4 N b) 2.4 N c) 3.4 N d) 6.4 N
Last Answer : a) 5.4 N
Description : Electron can exist in the atom but outside the nucleus because a) speed of electron is equal to the speed of light b) speed of electron is more than speed of light c) speed of electron is less than speed of light d) None of these
Last Answer : c) speed of electron is less than speed of light
Description : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c
Last Answer : d) both a & c
Description : The quantized Bohr orbit radius of electron in hydrogen atom is given by a) n2 r3 b) nr1 c) n2 r2 d) n2 r1
Last Answer : d) n2 r1
Description : The value of first quantized Bohr orbit radius of hydrogen atom is a) 0.0053 nm b) 5.3 nm c) 0.053 nm d) 0.053 cm
Last Answer : c) 0.053 nm
Description : For Hydrogen atom, the allowed stationary orbits are those whose orbital angular momentum is equal to an integral multiple of h i.e., mvr = a) nh/2π b) nh x 2π c) nh / 2λ d) nh / 2πλ
Last Answer : a) nh/2π
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 : A smallest three dimensional part of a crystal lattice is called. a) A particle b) A molecules c) A unit cell d) An atom
Last Answer : c) A unit cell
Description : A hydrogen like atom (atomic number Z) is in a higher excited state of quantum number n. The excited atom can make a transition to the first excited s
Last Answer : A hydrogen like atom (atomic number Z) is in a higher excited state of quantum number n. The excited ... . (lonization energy of H-atom = 13.6 eV)
Description : Consider a hydrogen-like atom whose energy in nth excited state is given by `E_(n) = (13.6 Z^(2))/(n^(2))` When this excited makes a transition from e
Last Answer : Consider a hydrogen-like atom whose energy in nth excited state is given by `E_(n) = (13. ... number of atom and the intial state or excitation.
Description : Hydrogen atom is excited from ground state to another state with principal quantum number equal to 4. Then the number of spectral lines in the emission spectra will be - (1) 2 (2) 6 (3) 5 (4) 3
Last Answer : (2) 6 Explanation: Number of spectral lines from a state n to ground state is = n (n-1)/2 =4(4-1)/2 =12/2 =6
Description : Which one of the following statements is WRONG? (A) A singlet or triplet state may result when one of the electrons from the HOMO is excited to higher energy levels (B) In an ... the electron from the singlet excited state returns to ground state, the molecule always shows fluorescence phenomenon
Last Answer : (C) Triplet excited state is more stable than the singlet excited state
Description : In transistor, the base region is of the order of _______ (a) 10-5 m (b) 10-2 m (c) 10-8 m (d) 10-6 m
Last Answer : d) 10-6 m
Description : A hydrogen atom in a having a binding of `0.85eV`makes transition to a state with excited energy `10.2eV`(a) identify the quantum number n of theupper
Last Answer : A hydrogen atom in a having a binding of `0.85eV`makes transition to a state with excited ... (b) Find the wavelength of the emitted radiation
Description : The transfer function of a system is 10/(1+s) when operating as a unity feedback system, the steady state error to a step input will be a) 0 b) 1/11 c) 10 d) Infinity
Last Answer : Ans: 1/11
Description : The color code of green is a. 8 b. 3 c. 5 d. 7
Last Answer : c. 5
Description : An α particle moves perpendicular to a constant magnetic field of strength 1.2 T in a circular path of radius 0.7 m. The speed of α particle in ms-1 is ______________ a) 2.7 × 107 b) 2.6 × 107 c) 3.2 × 107 d) 2.0 × 107
Last Answer : a) 2.7 × 107
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 : For the production of X-rays, the electrons which strike with the target are a) slow moving b) fast moving c) vibrational electrons d) free electrons
Last Answer : b) fast moving
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 : 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 quantities is conserved in pair production? a) Energy b) Charge c) Linear momentum d) All
Last Answer : d) All
Description : The value of Rydberg’s constant is a) 1.0974 x 10-7 m-1 b) 1.0974 x 107 m-1 c) 1.0974 x 107 m-2 d) 1.0974 x 10-7 m-2
Last Answer : b) 1.0974 x 107 m-1
Description : An electrical circuit with 10 branches and 7 junctions will have
Last Answer : An electrical circuit with 10 branches and 7 junctions will have 4 loop equations.
Description : An electron collides with a fixed hydrogen atom in its ground state. Hydrogen atom gets excited and the colliding electron loses all its kinetic energ
Last Answer : An electron collides with a fixed hydrogen atom in its ground state. Hydrogen atom gets excited and the colliding ... eV C. 12.1 eV D. 13.6 eV
Description : Hydrogen atom electron is excited to n = 4 state , in the spectrum of emitted radiation , number of lines in the ultravoilet and visible regions are r
Last Answer : Hydrogen atom electron is excited to n = 4 state , in the spectrum of emitted radiation , number of lines in the ... 1 , 3 C. 2 , 3 D. 3 , 2
Description : The energy required to excite an electron from the ground state of hydrogen atom to the first excited state, is
Last Answer : The energy required to excite an electron from the ground state of hydrogen atom to the first excited state, is A. ... 10.2 eV C. 0.85 eV D. 12.75eV
Description : An electron , in a hydrogen-like atom, is in excited state. It has a total energy of -3.4 eV. Calculate (a) the kinetic energy and (b) the de Broglie
Last Answer : An electron , in a hydrogen-like atom, is in excited state. It has a total energy of -3.4 ... and (b) the de Broglie wavelength of the electron.
Description : A hydrogen like atom (atomic number `z`) is in a higher excited state of quantum number `n`. This excited atom can make a transition to the first exci
Last Answer : A hydrogen like atom (atomic number `z`) is in a higher excited state of quantum number `n`. This ... eV` respectively. Determine the value of `(n+z)`