Description : (2) experience collision less frequently Explanation: When an electric field is applied, both the valence electrons and the free electrons move in the same direction. The hole direction is opposite to that ... to free electrons. This means mobility is also less for a hole compared to free electron.
Last Answer : Carbon dioxide is called a greenhouse gas because - (1) its concentration remains always higher than other gases (2) it is used in photosynthesis (3) it absorbs infrared radiation (4) it emits visible radiation
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 : An electron is travelling at right angles to a uniform magnetic field of flux density 1.2 mT with a speed of 8 × 106 m s-1, the radius of circular path followed by electron is A. 3.8 cm B. 3.7 cm C. 3.6 cm D. 3.5 cm
Last Answer : 3.8 cm
Description : Find the band gap energy when a light of wavelength 1240nm is incident on it. a) 1eV b) 2eV c) 3eV d) 4eV
Last Answer : a) 1eV
Description : A current of 2 A is made to flow through a coil which has only one turn. The magnetic field produced at the centre is`4pi xx 10^(-6) "Wb"//m^(2).` the
Last Answer : A current of 2 A is made to flow through a coil which has only one turn. The magnetic field produced at the centre is` ... m` C. `0.1 m` D. `0.001 m`
Description : An electron is moving in a circular path under the influence fo a transerve magnetic field of `3.57xx10^(-2)T`. If the value of `e//m` is `1.76xx10^(1
Last Answer : An electron is moving in a circular path under the influence fo a transerve magnetic field of `3.57xx10^(-2)T`. ... MHz` C. `62.8 MHz` D. `6.28MHz`
Description : An electron is moving on a circular path of radius `r` with speed `v` in a transverse magnetic field B. e/m for it will be
Last Answer : An electron is moving on a circular path of radius `r` with speed `v` in a transverse magnetic field B. e/m for it ... /Br` B. `B/rv` C. Brv D. `vr/B`
Description : A long straight wire is carrying a current of 12 A . The magnetic field at a distance of 8 cm is `(mu_(0) =4pi xx 10^(-7) N A ^(2))`
Last Answer : A long straight wire is carrying a current of 12 A . The magnetic field at a distance of 8 cm is `(mu_(0) =4pi xx ... /m^(2)` D. `4xx10^(-5)Wb//m^(2)`
Description : Electrons move at right angles to a magnetic field of `1.5xx10^(-2)` Tesla with a speed of `6xx10^(7)m//s`. If the specific charge of the electron is
Last Answer : Electrons move at right angles to a magnetic field of `1.5xx10^(-2)` Tesla with a speed of `6xx10^ ... C//kg`. The radius of the circular path will be
Description : A glass prism has a refracting angle of `60^@`. The angle of minimum deviation is `40^@`. If velocity of light in vacuum is `3 xx 10^8 m//s`. Calculat
Last Answer : A glass prism has a refracting angle of `60^@`. The angle of minimum deviation is `40^@`. If ... of light in glass. What is the angle of incidence ?
Description : An electron moving with a velocity of 5 10 3 m / s enters into a uniform electric field and acquires a uniform acceleration of 10 3 m / s 2 in the direction of initial velocity. i. ... which electron velocity will be doubled.? ii. How much distance electron would cover in this time.? -Science
Last Answer : Given u=5×103m/su=5×103m/s , a=103m/s2a=103m/s2, v=2u=104v=2u=104 m/s i.Using v=u+atv=u+at 104=5×103+103t104=5×103+103t or t=5 sec ii. Using s=ut+12at2s=ut+12at2 s=5×103×5+12×103×52s=5×103×5+12×103×52 =37.5×103m=37.5×103m
Description : If a gas absorbs `200J` of heat and expands by `500 cm^(3)` against a constant pressure of `2 xx 10^(5) N m^(-2)`, then the change in internal energy
Last Answer : If a gas absorbs `200J` of heat and expands by `500 cm^(3)` against a constant pressure of `2 xx 10^(5) N ... . `-100 J` C. `+100 J` D. None of these
Description : An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is `5 xx 10^(-4)` phot. Th
Last Answer : An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the ... ? (1 phot `= 1m//cm^(2))`.
Description : It has been estimated that the total energy ratiated by sun is `3.8 xx 10^(26)` j per second. The source of energy of stars is a thermonuclear reactio
Last Answer : It has been estimated that the total energy ratiated by sun is `3.8 xx 10^(26)` j per second. The source of ... B. 26.9 MeV C. 23.6 MeV D. 19.2 MeV
Description : Find the time of relaxation between collsion and free path of electrons in copper at room temperature. Given resistivity of copper`=1.7xx10^(-8) Omega
Last Answer : Find the time of relaxation between collsion and free path of electrons in copper at room temperature. Given ... electrons`=1.6xx10^(-4) ms^(-1)`
Description : Iluminance of `2.4 xx 10^(5)lm//m^(2)` of the surface is produced by sunlight falling normally on the surface of the earth. The distance of the earth
Last Answer : Iluminance of `2.4 xx 10^(5)lm//m^(2)` of the surface is produced by sunlight ... Calculate the luminous intensity and luminous flux of the sun.
Description : An electron and a proton are moving at the same speed in circular paths in the same uniform magnetic field. The radius of the path of the proton is one of the following. Is this radius: w) the same ... of the electron y) a little larger than that of the electron z) smaller than that of the electron
Last Answer : ANSWER: X -- ABOUT 2000 TIMES LARGER THAN THAT OF THE ELECTRON
Description : Assertion If the path of a charged particle in a region of uniform electric and magnetic field is not a circle, then its kinetic energy may remain con
Last Answer : Assertion If the path of a charged particle in a region of uniform electric and magnetic field is ... VxxB),` where symbols have their usual meanings.
Description : Calculate the electric field when the conductivity is 20 units, electron density is 2.4 units and the velocity is 10m/s. Assume the conduction and convection current densities are same. a) 2.4 b) 4.8 c) 3.6 d) 1.2
Last Answer : d) 1.2
Description : The process, whereby electrons gain sufficient energy to be released from the surface of a thin, heated metal plate, is known as _____________. A. photo electric emission B. secondary emission C. thermionic emission D. regressive emission
Last Answer : Answer: C
Description : When an electronl beam passes through and electric field they gain kinetic energy. If the same electron beam passes through a magnetic field then thei
Last Answer : When an electronl beam passes through and electric field they gain kinetic energy. If the same ... C. momentum increases D. kinetic energy increases
Description : Find the mean free path of an electron travelling at a speed of 18m/s in 2 seconds. a) 9 b) 36 c) 0.11 d) 4.5
Last Answer : b) 36
Description : The constant-speed electrons of an electron bunch in a reflex klystron must remain in the repeller field for what minimum time?
Last Answer : Three-quarter cycle.
Description : The orbital angular momemtum quantum number indicates which one of the following? w) the average distance of the electrons from the nucleus x) the direction of spin of the electron y) the shape of the orbital z) the position about the three axes in space of the orbital
Last Answer : ANSWER: Y -- THE SHAPE OF THE ORBITAL
Description : The velocity of light in glass is `2 xx 10^(8)ms^(-1)` while that in vaccum is `3 xx 10^(8)ms^(-1)`. By how much would an ink dot appeat to be raised
Last Answer : The velocity of light in glass is `2 xx 10^(8)ms^(-1)` while that in vaccum is `3 xx 10^ ... raised when covered by a glass plate of 4.5 cm thickness.
Description : A reaction develop nuclear energy at the rate of `3 xx 10^(4) kW`. How many atoms of `.^(215)U` undergo fission per second? How much `.^(235)U` is bur
Last Answer : A reaction develop nuclear energy at the rate of `3 xx 10^(4) kW`. How many atoms of `.^(215)U` ... constant is `6.023 xx 10^(26)` per kg mole)
Description : The base of a cubical tank is `25 m xx 40 m`. The volume of water in the tank is increasing at the rate of `500 m^(3)//min`. Find the rate at which th
Last Answer : The base of a cubical tank is `25 m xx 40 m`. The volume of water in the tank is ... Find the rate at which the height of water is increasing.
Description : If `((x^(m)xx x^(n))/x^(p))^(q)=x^(k)`, then `k=` ________.
Last Answer : If `((x^(m)xx x^(n))/x^(p))^(q)=x^(k)`, then `k=` ________.
Description : At room temperature copper has free electron density of `8.4xx10^(28) per m^(3)` . The copper conductor has a cross-section of `10^(-6)m^(2)` and carr
Last Answer : At room temperature copper has free electron density of `8.4xx10^(28) per m^(3)` . The copper conductor has a cross ... . `4cms^(-1)` D. `0.4mms^(-1)`
Description : A particle carrying a charge equal to `100` times the charge on an electron is rotating per second in a circular path of radius `0.8 metre`. The value
Last Answer : A particle carrying a charge equal to `100` times the charge on an electron is rotating per second in a circular path ... 6)mu_(0)` D. `10^(-7)mu_(0)`
Description : A nonrelativistic electron enters a uniform magnetic field of 50 mT with a speed of `10^(6) m//s` at right angles to it and emerges from the field aft
Last Answer : A nonrelativistic electron enters a uniform magnetic field of 50 mT with a speed of `10^(6) m/ ... not depend on the initial speed of the electron.
Description : A point charge q moves from A to B along a parabolic(x2 =2ay) path (AB is latus rectum). Electric field is along x-axis. The work done by the field is
Last Answer : A point charge q moves from A to B along a parabolic(x2 =2ay) path (AB is latus rectum). Electric field is ... qEa` B. `+qEa` C. `-2qEa` D. `2qEa`
Description : An electric field is given as E = 6y 2 z i + 12xyz j + 6xy 2 k. An incremental path is given by dl = -3 i + 5 j – 2 k mm. The work done in moving a 2mC charge along the path if the location of the path is at p(0,2,5) is (in Joule) a) 0.64 b) 0.72 c) 0.78 d) 0.80
Last Answer : b) 0.72
Description : Electrons which are free to move around are also called A. conduction electrons B. valence shell electrons C. inner electrons D. electron sea
Last Answer : conduction electrons
Description : When radiation breaks an electron pair bond in a molecule and each fragment of the molecule gets one of the bond electrons, the molecular fragments that are formed are called: w) ions x) free radicals y) stable molecules z) gases
Last Answer : ANSWER: X -- FREE RADICALS
Description : A proton of energy `8 eV` is moving in a circular path in a uniform magnetic field. The energy of an alpha particle moving in the same magnetic field
Last Answer : A proton of energy `8 eV` is moving in a circular path in a uniform magnetic field. The energy of an alpha ... will be A. 4eV B. 22eV C. 8eV D. 6eV
Description : Electric current in a metal wire is due to the flow of — (1) Electrons (2) Protons (3) Ions (4) Holes
Last Answer : (1) Electrons Explanation: A solid conductive metal contains mobile, or free electrons, originating in the conduction electrons. When a metal wire is connected across the two terminals of a DC ... the conductor are forced to drift toward the positive terminal under the influence of this field.
Description : Electric current in a metal wire is due to the flow of— (1) Electrons (2) Protons (3) Ions (4) Holes
Last Answer : Electrons
Description : Electron are emitted from an electron gun at almost zero velocity and are accelerated by an electric field `E` through a distance of `1.0m` The electr
Last Answer : Electron are emitted from an electron gun at almost zero velocity and are accelerated by an electric field ... .5 nm` may be emitted by the hydrogen?
Description : Pick out the wrong statement. (A) The X-rays cannot be deflected by electric field unlike cathode rays (B) The intensity of X-rays can be measured by ionisation current produced due to the ... the anode-cathode voltage (D) Crystal structure of a material can be studied by an electron microscope
Last Answer : (C) The quality of X-rays can be controlled by varying the anode-cathode voltage
Description : Who received the Nobel Prize in Physics in 1923 for his experiment which measured the charge of the electron. The experiment consisted of allowing drops of oil which had become charged to fall in an electric field.
Last Answer : ANSWER: (ROBERT ANDREWS) MILLIKAN
Description : How does energy of core electrons compare with the energy of valence electron?
Last Answer : The energy is higher.
Description : An electron microscope gives higher magnification than an optical microscope, because: (1) It uses more powerful lenses (2) the velocity of electron is smaller than that of visible (3) the ... particles (4) the wavelength of electrons is smaller as compared to the wavelength of visible light
Last Answer : (4) the wavelength of electrons is smaller as compared to the wavelength of visible light Explanation: An electron microscope uses a beam of electrons to illuminate a specimen and produce a ... photons. Magnification is the process of enlarging something only in appearance, not in physical size.
Description : An electron microscope gives higher magnifications than an optical microscope because - (1) The velocity of electrons is smaller than that of light (2) The wavelength of electrons is smaller as ... have more energy than the light particulars (4) The electron microscope uses more powerful lenses
Last Answer : (2) The wavelength of electrons is smaller as compared to the wavelength of visible light Explanation: An electron microscope is a microscope that uses a beam of accelerated electrons as a spume ... a higher resolving power than a light microscope and can reveal the structure of smaller objects.
Description : The acquisition energy by glucose fermentation requires A.substrate-level phosphorylation B.electron transport of electrons from NADH C.long-chain fatty acid oxidation D.the enzyme formic-hydrogen lyase
Last Answer : A.substrate-level phosphorylation
Description : Most of the energy in aerobic respiration of glucose is captured by A- substrate-level phosphorylation B- electron transport of electrons from NADH C- long-chain fatty acid oxidation D- the enzyme formic-hydrogen lyase
Last Answer : electron transport of electrons from NADH
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 : An electron microscope gives higher magnifications than an optical microscope because : (1) The velocity of electrons is smaller than that of light (2) The wavelength of electrons is smaller as ... have more energy than the light particulars (4) The electron microscope uses more powerful lenses
Last Answer : The wavelength of electrons is smaller as compared to the wavelength of visible light
Description : An electron microscope gives higher magnification than an optical microscope, because : (1) it uses more powerful lenses (2) the velocity of electron is smaller than that of visible light (3) ... particles (4) the wavelength of electrons is smaller as compared to the wavelength of visible light
Last Answer : the wavelength of electrons is smaller as compared to the wavelength of visible light
Description : Find the electric field applied on a system with electrons having a velocity 5m/s subjected to a magnetic flux of 3.6 units. a) 15 b) 18 c) 1.38 d) 0.72
Last Answer : b) 18