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 amount of energy required to completely remove an electron from the first Bohr orbit is a) 13.6 MeV b) 13.6 eV c) 1.36 MeV d) 1.36 eV
Last Answer : b) 13.6 eV
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 : 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 : A proton moves in a uniform magnetic field in a circular path of radius R. If the energy of proton is doubled then the new radius becomes a) R √2 b) 2R c) R 2 d) √2 R
Last Answer : d) √2 R
Description : Calculate the speed of the electron in the first Bohr orbit given that `h=6.6xx10^(-34) Js, m=9.11xx10^(-31) kg` and `e=1.603xx10^(-19) C`.
Last Answer : Calculate the speed of the electron in the first Bohr orbit given that `h=6.6xx10^(-34) Js, m=9.11xx10^(-31) kg` and `e=1.603xx10^(-19) C`.
Description : Three resistors of resistance R are connected in various ways, which of the following cannot be obtained? a. 3R ohm b. 2R/4 ohm c. R/3 ohm d. 2R/3 ohm
Last Answer : b. 2R/4 ohm
Description : The de-Broglie wavelength of an electron moving in the nth Bohr orbit of radius ris given by
Last Answer : The de-Broglie wavelength of an electron moving in the nth Bohr orbit of radius ris given by A. `(2pir)/n` B. `npir` C. `(nr)/(2pi)` D. `(nr)/pi`
Description : The speed of hydrogen electron in the nth orbit is given by vn = a) 2λke2 / nh b) 2πke2 / λh c) 2πke2 / nh d) 2πke2 / h
Last Answer : c) 2πke2
Description : Calculate the radius of the first Bohr orbit of a `He^(+)` ion and the binding energy of its electron in the ground state.
Last Answer : Calculate the radius of the first Bohr orbit of a `He^(+)` ion and the binding energy of its electron in the ground state.
Description : Electrical energy is converted to heat at the rate of a. IRt b. I 2R c. I 2Rt d. VIt
Last Answer : b. I 2R
Description : The average current due to an electron orbiting the proton in the `n^(th)` Bohr orbit of the hydrogen atom is
Last Answer : The average current due to an electron orbiting the proton in the `n^(th)` Bohr orbit of the hydrogen atom ... `propn^3` C. `propb` D. none of these
Description : According to Bohr's theory, an electron in one Bohr stationary orbit can go to a higher stationary orbit (a) By emission of electromagnetic radiation (b) Without any absorption ... absorption of any electromagnetic radiation (d) With absorption of electromagnetic radiation of a particular frequency
Last Answer : Ans:(d)
Description : A particle of mass `m` moves along a circular orbit in centrosymmetrical potential field `U(r )=kr^(2)//2`. Using the Bohr quantization condition, fin
Last Answer : A particle of mass `m` moves along a circular orbit in centrosymmetrical potential field `U(r ... orbital radii and energy levels to that particle.
Description : Calculate the energy of hydrogen atom in the ground state given that the after Bohr orbit og hydrogen is `5xx10^(-11)m` and electronic charge is `1.6x
Last Answer : Calculate the energy of hydrogen atom in the ground state given that the after Bohr orbit og hydrogen is ` ... electronic charge is `1.6xx10^(-19) C`.
Description : The radius of Gyration (k) for Rim Type Flywheel having radius ‘r’ is given by 1. k = 2r 2. k = r/2 3. k = r 4. k = r/3
Last Answer : 3. k = r
Description : If r is the radius of a circle and d is its diameter is an equivalent formula for the circumference C 2r?
Last Answer : Circumference of a circle: 2*pi*radius or diameter*pi
Description : The approximate formula for radial or perpendicular offsets from the tangent, is (A) x/2R (B) x²/2R (C) x/R (D) x²/R
Last Answer : (B) x²/2R
Description : The product of uncertainties of two physical observables must be approximately equal to a)Coulomb’s constant K b) Rydberg’s constant R c)Planck’s constant d)All of the above
Last Answer : c)Planck’s constant
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 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 minimum energy required to eject an electron from a metal surface is called a) Intensity b) Threshold frequency c) Work function d) Photo energy
Last Answer : c) Work function
Description : If energy of incident photon is greater than the rest mass energy of electron positron pair, the surplus energy is shared by the pair as, a) Potential energy b) Thermal energy c) Electronic energy d) Kinetic energy
Last Answer : d) Kinetic energy
Description : Degree of kinematic indeterminacy of a pin-jointed plane frame is given by (A) 2j - r (B) j - 2r (C) 3j - r (D) 2j + r
Last Answer : (A) 2j - r
Description : Below are the few steps given for scan-converting a circle using Bresenham's Algorithm. Which of the given steps is not correct? (1) Compute d = 3 – 2r (where r is radius) (2) Stop if x> y (3) If d
Last Answer : If d≥0,then d=4 *(x-y)+10, x=x+1 and y=y+1
Description : The angular momentum J of the electron in a hydrogen atom is proportional to `n^(th)` power of r (radius of the orbit) where n is :-
Last Answer : The angular momentum J of the electron in a hydrogen atom is proportional to `n^(th)` power of r (radius of the orbit ... B. `-1` C. `(1)/(2)` D. None
Description : An electron moving in a circular orbit of radius `r` makes `n` rotation per secound. The magnetic field produced at the centre has magnitude
Last Answer : An electron moving in a circular orbit of radius `r` makes `n` rotation per secound. The magnetic field produced at ... (r)` D. `(mu_(0)"ne")/(2r)`
Description : The collision between a photon and a free electron was first explained by which of the following scientists? w) Einstein x) Heisenberg y) Compton z) Bohr
Last Answer : ANSWER: Y -- COMPTON
Description : The force in a medium of relative permitivity ∈r is given by: (a) F′ =F (b) F′ =∈r ∈ F r (c) F′ = ∈r . F (d) F′ =F ∈ ∈
Last Answer : (a) F′ =F
Description : If electron has to be confined in the nucleus, its speed would have to be greater than a) 1010 cm/s b) 1010 m/s c) 1020 m/s d) 1020 cm/s
Last Answer : b) 1010 m/s
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 : A three dimensional image is obtained by a)Electron microscope b) Scanning electron microscope c) Magnetic imaging d)None of these
Last Answer : b) Scanning electron microscope
Description : The electron was discovered by a) Burcherer b) Anderson c) Chadwick d) J. J Thomson
Last Answer : d) J. J Thomson
Description : An electron moves with a velocity of 2 × 106 ms-1 in the direction of a uniform magnetic field of 0.8 Tesla. The force on electron is a) 8 N b) 2 N c) 4 N d) Zero
Last Answer : d) Zero
Description : A circuit which develops voltage across the horizontal deflection plates is known as a) Time base generator b) Electron gun c) Thermionic diode d) Zener diode
Last Answer : a) Time base generator
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 : Two electron beams move parallel to each other. The nature of force between them is a) Attractive b) Repulsive c) Dependent on magnitude of velocity d) None
Last Answer : b) Repulsive
Description : An electron and a neutron enter a magnetic field with the same velocity. Ratio of electron to neutron’s acceleration is a) mn me b) √ mn me c) √ me mn d) me
Last Answer : a) mn me
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 : Centroid of the are of circle shown in adjacement figure is a.r sin (?/2)/2 ?, 0 b.r sin (?)/?, 0 c.2 r sin (?/2)/?, 0 d.107 dynes e.2r sin (?)/?, 0
Last Answer : c. 2 r sin (?/2)/?, 0
Description : Calculate the frequency of revolution of an electron in the first orbit of an aluminum atom. Given that mass of electron `=9x10^(-31) kg, e= 1.6 xx10^
Last Answer : Calculate the frequency of revolution of an electron in the first orbit of an aluminum atom. Given that mass of ... of the orbit `=0.2xx10^(-11) m`.
Description : Thermistor with high negative temperature coefficient are very accurate for measuring low temperature especially near is a. 10 K b. 70K c. 200K d. 35K
Last Answer : c. 200K
Description : Sometimes, when you change the running direction of a E/R blower (from supply to exhaust) it trips. Why?
Last Answer : If the flaps of the blower are not set or opened properly or the filters are clogged, the air supply is affected and the blower may be overloaded causing it to trip. Ask E/O for more information.
Description : The relativistic energy ‘E’ is equivalent to relativistic mass given by a) Ec2 b) 2 c E c) c E d) E c
Last Answer : b) 2 c E
Description : If `(2p+5q)/(2r+5s) = (4p-3q)/(4r-3s)`, then find the relation between p, q, r and s.
Last Answer : If `(2p+5q)/(2r+5s) = (4p-3q)/(4r-3s)`, then find the relation between p, q, r and s.
Description : In the circuit diagram,heat produces in R, 2R and `1.5 R` are in the ratio of
Last Answer : In the circuit diagram,heat produces in R, 2R and `1.5 R` are in the ratio of A. `4:2:3` B. `8:4:27` C. `2:4:3` D. `27:8:4`
Description : Weight of a person at a height of 2R from the centre of the earth, where R is the radius of the earth- (1) remains same (2) becomes half (3) becomes twice (4) becomes one-fourth
Last Answer : (4) becomes one-fourth Explanation: The gravitational force is proportional to 1/R2, where R is the distance from the centre of the Earth. So at a height of 2R from the centre of the earth, the corresponding weight would be one-fourth of the original weight.
Description : If a wire of resistance R is melted and recast to half of its length, then the new resistance of the wire will be - (1) R/4 (2) R/2 (3) R (4) 2R
Last Answer : (1) R/4
Description : A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ρL) located at a radial distance R from the axis of rotation. The thickness of the liquid film is δ and no cake is formed. The ... . ρL (C) ½w 2 . δρL (2R + δ) (D) ½w 2 . R . ρL(R + 2δ)
Last Answer : (C) ½w 2 . δρL (2R + δ)