-
question_answer1)
In the Millikan's experiment, the distance between two horizontal plates is 2.5 cm and the potential difference applied is 250 V. The electric field between the plates will be
A)
900 V/m done
clear
B)
10000 V/m done
clear
C)
625 V/m done
clear
D)
6250 V/m done
clear
View Solution play_arrow
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question_answer2)
The cathode rays have particle nature because of the fact that [CPMT 1986; MNR 1986]
A)
They can propagate in vacuum done
clear
B)
They are deflected by electric and magnetic fields done
clear
C)
They produced fluorescence done
clear
D)
They cast shadows done
clear
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question_answer3)
In Millikan's experiment for the determination of the charge on the electron, the reason for using the oil is
A)
It is a lubricant done
clear
B)
Its density is higher done
clear
C)
It vapourises easily done
clear
D)
It does not vapourise done
clear
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question_answer4)
The mass of a particle is 400 times than that of an electron and the charge is double. The particle is accelerated by 5 V. Initially the particle remained in rest, then its final kinetic energy will be [MP PMT 1990]
A)
5 eV done
clear
B)
10 eV done
clear
C)
100 eV done
clear
D)
2000 eV done
clear
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question_answer5)
An electron (charge =\[1.6\times {{10}^{-19}}C\]) is accelerated through a potential of 100,000 V. The energy acquired by the electron is [MP PET 1989]
A)
\[1.6\times {{10}^{-24}}\ J\] done
clear
B)
\[1.6\times {{10}^{-14}}\ erg\] done
clear
C)
\[0.53\times {{10}^{-17}}J\] done
clear
D)
\[1.6\times {{10}^{-14}}J\] done
clear
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question_answer6)
While doing his experiment, Millikan one day observed the following charges on a single drop (i) \[6.563\times {{10}^{-19}}C\] (ii) \[8.204\times {{10}^{-19}}C\] (iii) \[11.50\times {{10}^{-19}}C\] (iv) \[13.13\times {{10}^{-19}}C\] (v) \[16.48\times {{10}^{-19}}C\] (vi) \[18.09\times {{10}^{-19}}C\] From this data the value of the elementary charge (e) was found to be [MP PMT 1993]
A)
\[1.641\times {{10}^{-19}}C\] done
clear
B)
\[1.630\times {{10}^{-19}}C\] done
clear
C)
\[1.648\times {{10}^{-19}}C\] done
clear
D)
\[1.602\times {{10}^{-19}}C\] done
clear
View Solution play_arrow
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question_answer7)
When electron beam passes through an electric field, they gain kinetic energy. If the same beam passes through magnetic field, then
A)
Their energy increases done
clear
B)
Their momentum increases done
clear
C)
Their potential energy increases done
clear
D)
Energy and momentum both remains unchanged done
clear
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question_answer8)
Which of the following law is used in the Millikan's method for the determination of charge [DPMT 2002]
A)
Ampere's law done
clear
B)
Stoke's law done
clear
C)
Fleming's left hand rule done
clear
D)
Fleming's right hand rule done
clear
View Solution play_arrow
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question_answer9)
The mass of the electron varies with
A)
The size of the cathode ray tube done
clear
B)
The variation of ?g? done
clear
C)
Velocity done
clear
D)
Size of the electron done
clear
View Solution play_arrow
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question_answer10)
When the speed of electrons increases, then the value of its specific charge [MP PMT 1994]
A)
Increases done
clear
B)
Decreases done
clear
C)
Remains unchanged done
clear
D)
Increases upto some velocity and then begins to decrease done
clear
View Solution play_arrow
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question_answer11)
An electron is accelerated through a potential difference of 1000 volts. Its velocity is nearly [MP PMT 1985; Pb. PET 2003]
A)
\[\frac{{{\nu }_{1}}-{{\nu }_{2}}}{k-1}\] done
clear
B)
\[1.9\times {{10}^{6}}m/s\] done
clear
C)
\[1.9\times {{10}^{7}}m/s\] done
clear
D)
\[2\sqrt{2}V\] done
clear
View Solution play_arrow
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question_answer12)
In an electron gun the control grid is given a negative potential relative to cathode in order to [NCERT 1988]
A)
Decelerate electrons done
clear
B)
Repel electrons and thus to control the number of electrons passing through it done
clear
C)
To select electrons of same velocity and to converge them along the axis done
clear
D)
To decrease the kinetic energy of electrons done
clear
View Solution play_arrow
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question_answer13)
The ratio of momenta of an electron and an \[\alpha -\]particle which are accelerated from rest by a potential difference of 100 V is [MNR 1994; RPET 1997]
A)
1 done
clear
B)
\[\sqrt{\frac{2{{m}_{e}}}{{{m}_{\alpha }}}}\] done
clear
C)
\[\sqrt{\frac{{{m}_{e}}}{{{m}_{\alpha }}}}\] done
clear
D)
\[\sqrt{\frac{{{m}_{e}}}{2{{m}_{\alpha }}}}\] done
clear
View Solution play_arrow
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question_answer14)
When subjected to a transverse electric field, cathode rays move [MP PET 1994]
A)
Down the potential gradient done
clear
B)
Up the potential gradient done
clear
C)
Along a hyperbolic path done
clear
D)
Along a circular path done
clear
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question_answer15)
The fact that electric charges are integral multiples of the fundamental electronic charge was proved experimentally by [MP PET 1994]
A)
Planck done
clear
B)
J.J. Thomson done
clear
C)
Einstein done
clear
D)
Millikan done
clear
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question_answer16)
In Millikan oil drop experiment, a charged drop of mass \[1.8\times {{10}^{-14}}kg\]is stationary between its plates. The distance between its plates is 0.90 cm and potential difference is 2.0 kilo volts. The number of electrons on the drop is [MP PMT 1994, 2003; MP PET 1997]
A)
500 done
clear
B)
50 done
clear
C)
5 done
clear
D)
0 done
clear
View Solution play_arrow
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question_answer17)
The charge on electron was discovered by [BHU 1995; RPMT 1999; DCE 2004]
A)
J.J. Thomson done
clear
B)
Neil Bohr done
clear
C)
Millikan done
clear
D)
Chadwick done
clear
View Solution play_arrow
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question_answer18)
From the following, what charges can be present on oil drops in Millikan's experiment [MP PET 1995]
A)
Zero, equal to the magnitude of charge on \[\alpha -\]particle done
clear
B)
\[2e,\ 1.6\times {{10}^{-18}}C,\] done
clear
C)
\[1.6\times {{10}^{-19}}C,\ 2.5e\] done
clear
D)
\[1.5e,\ e\] (Here e is the electronic charge) done
clear
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question_answer19)
A narrow electron beam passes undeviated through an electric field \[E=3\times {{10}^{4}}volt/m\]and an overlapping magnetic field \[B=2\times {{10}^{-3}}Weber/{{m}^{2}}\]. If electric field and magnetic field are mutually perpendicular. The speed of the electrons is [MP PET 1995]
A)
60 m/s done
clear
B)
\[10.3\times {{10}^{7}}m/s\] done
clear
C)
\[1.5\times {{10}^{7}}m/s\] done
clear
D)
\[0.67\times {{10}^{-7}}m/s\] done
clear
View Solution play_arrow
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question_answer20)
In Thomson's method of determining e/m of electrons [MP PMT 1997
A)
Electric and magnetic fields are parallel to electrons beam done
clear
B)
Electric and magnetic fields are perpendicular to each other and perpendicular to electrons beam done
clear
C)
Magnetic field is parallel to the electrons beam done
clear
D)
Electric field is parallel to the electrons beam done
clear
View Solution play_arrow
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question_answer21)
Cathode rays enter into a uniform magnetic field perpendicular to the direction of the field. In the magnetic field their path will be [MP PMT/PET 1998]
A)
Straight line done
clear
B)
Circle done
clear
C)
Parabolic done
clear
D)
Ellipse done
clear
View Solution play_arrow
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question_answer22)
The specific charge of an electron is [MP PMT/PET 1998; J&K CET 2004; Pb. PET 2002; MH CET 1999]
A)
\[1.6\times {{10}^{-19}}coulomb\] done
clear
B)
\[4.8\times {{10}^{-10}}stat\ coulomb\] done
clear
C)
\[1.76\times {{10}^{11}}coulomb/kg\] done
clear
D)
\[|8|\times {{10}^{-15}}Hz\] done
clear
View Solution play_arrow
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question_answer23)
An electron is moving with constant velocity along \[x-\]axis. If a uniform electric field is applied along \[y-\]axis, then its path in the \[x-y\] plane will be [MP PMT 1999]
A)
A straight line done
clear
B)
A circle done
clear
C)
A parabola done
clear
D)
An ellipse done
clear
View Solution play_arrow
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question_answer24)
Cathode rays are similar to visible light rays in that [SCRA 1994]
A)
They both can be deflected by electric and magnetic fields done
clear
B)
They both have a definite magnitude of wavelength done
clear
C)
They both can ionise a gas through which they pass done
clear
D)
They both can expose a photographic plate done
clear
View Solution play_arrow
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question_answer25)
Which one of the following devices makes use of the electrons to strike certain substances to produce fluorescence [SCRA 1994]
A)
Thermionic valve done
clear
B)
Photoelectric cell done
clear
C)
Cathode ray oscilloscope done
clear
D)
Electron gun done
clear
View Solution play_arrow
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question_answer26)
An oxide coated filament is useful in vacuum tubes because essentially [SCRA 1994]
A)
It has high melting point done
clear
B)
It can withstand high temperatures done
clear
C)
It has good machanical strength done
clear
D)
It can emit electrons at relatively lower temperatures done
clear
View Solution play_arrow
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question_answer27)
Gases begin to conduct electricity at low pressure because [CBSE PMT 1994]
A)
At low pressure, gases turn to plasma done
clear
B)
Colliding electrons can acquire higher kinetic energy due to increased mean free path leading to ionisation of atoms done
clear
C)
Atoms break up into electrons and protons done
clear
D)
The electrons in atoms can move freely at low pressure done
clear
View Solution play_arrow
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question_answer28)
A beam of electrons is moving with constant velocity in a region having electric and magnetic fields of strength \[20\ V{{m}^{-1}}\]and 0.5 T at right angles to the direction of motion of the electrons. What is the velocity of the electrons [CBSE PMT 1996]
A)
20 \[m{{s}^{-1}}\] done
clear
B)
40 \[m{{s}^{-1}}\] done
clear
C)
8 \[m{{s}^{-1}}\] done
clear
D)
5.5 \[m{{s}^{-1}}\] done
clear
View Solution play_arrow
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question_answer29)
Kinetic energy of emitted cathode rays is dependent on [CPMT 1996]
A)
Only voltage done
clear
B)
Only work function done
clear
C)
Both (a) and (b) done
clear
D)
It does not depend upon any physical quantity done
clear
View Solution play_arrow
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question_answer30)
The radius of the orbital of electron in the hydrogen atom 0.5 Å. The speed of the electron is \[2\times {{10}^{6}}m/s\]. Then the current in the loop due to the motion of the electron is [RPMT 1996]
A)
1 mA done
clear
B)
1.5 mA done
clear
C)
2.5 mA done
clear
D)
\[1.5\times {{10}^{-2}}mA\] done
clear
View Solution play_arrow
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question_answer31)
The kinetic energy of an electron which is accelerated through a potential of 100 volts is [MP PET 1986; CBSE PMT 1997; AIIMS 1998]
A)
\[1.602\times {{10}^{-17}}J\] done
clear
B)
418.6 calories done
clear
C)
\[1.16\times {{10}^{4}}K\] done
clear
D)
\[6.626\times {{10}^{-34}}\]W- sec done
clear
View Solution play_arrow
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question_answer32)
When a proton is accelerated with 1 volt potential difference, then its kinetic energy is [CPMT 1997; CBSE PMT 1999; RPET 2003]
A)
\[\frac{1}{1840}eV\] done
clear
B)
1840 eV done
clear
C)
1 eV done
clear
D)
1840 c2 eV done
clear
View Solution play_arrow
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question_answer33)
Energy of electrons can be increased by allowing them [JIPMER 1997]
A)
To fall through electric potential done
clear
B)
To move in high magnetic field done
clear
C)
To fall from great heights done
clear
D)
To pass through lead blocks done
clear
View Solution play_arrow
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question_answer34)
Cathode rays and canal rays produced in a certain discharge tube are deflected in the same direction if [SCRA 1998]
A)
A magnetic field is applied normally done
clear
B)
An electric field is applied normally done
clear
C)
An electric field is applied tangentially done
clear
D)
A magnetic field is applied tangentially done
clear
View Solution play_arrow
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question_answer35)
In a Millikan's oil drop experiment the charge on an oil drop is calculated to be \[6.35\times {{10}^{-19}}C\]. The number of excess electrons on the drop is [MNR 1998]
A)
3.9 done
clear
B)
4 done
clear
C)
4.2 done
clear
D)
6 done
clear
View Solution play_arrow
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question_answer36)
Cathode rays consist of [DCE 1999]
A)
Photons done
clear
B)
Electrons done
clear
C)
Protons done
clear
D)
\[\alpha \]-particles done
clear
View Solution play_arrow
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question_answer37)
A metal plate gets heated, when cathode rays strike against, it due to [CPMT 2000; Pb. PET 2000]
A)
Kinetic energy of cathode rays done
clear
B)
Potential energy of cathode rays done
clear
C)
Linear velocity of cathode rays done
clear
D)
Angular velocity of cathode rays done
clear
View Solution play_arrow
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question_answer38)
Cathode rays are [RPET 2000]
A)
Positive rays done
clear
B)
Neutral rays done
clear
C)
He rays done
clear
D)
Electron waves done
clear
View Solution play_arrow
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question_answer39)
An electron of charge ?e? coulomb passes through a potential difference of \[V\] volts. Its energy in ?joules? will be [MP PET 2000]
A)
\[V/e\] done
clear
B)
eV done
clear
C)
\[e/V\] done
clear
D)
V done
clear
View Solution play_arrow
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question_answer40)
An electron is accelerated through a potential difference of 200 volts. If \[e/m\] for the electron be \[1.6\times {{10}^{11}}\] coulomb/kg, the velocity acquired by the electron will be [MP PET 2000]
A)
\[8\times {{10}^{6}}\,m/s\] done
clear
B)
\[8\times {{10}^{5}}\,m/s\] done
clear
C)
\[5.9\times {{10}^{6}}\,m/s\] done
clear
D)
\[5.9\times {{10}^{5}}\,m/s\] done
clear
View Solution play_arrow
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question_answer41)
Which is not true with respect to the cathode rays [Kerala PET 2001]
A)
A stream of electrons done
clear
B)
Charged particles done
clear
C)
Move with speed same as that of light done
clear
D)
Can be deflected by magnetic fields done
clear
View Solution play_arrow
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question_answer42)
In Milikan?s experiment, an oil drop having charge q gets stationary on applying a potential difference V in between two plates separated by a distance ?d?. The weight of the drop is [MP PMT 2001]
A)
\[qVd\] done
clear
B)
\[q\frac{d}{V}\] done
clear
C)
\[\frac{q}{Vd}\] done
clear
D)
\[q\frac{V}{d}\] done
clear
View Solution play_arrow
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question_answer43)
Electron volt is a unit of [MP PMT 2001]
A)
Potential done
clear
B)
Charge done
clear
C)
Power done
clear
D)
Energy done
clear
View Solution play_arrow
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question_answer44)
In Thomson experiment of finding \[e/m\] for electrons, beam of electron is replaced by that of muons (particle with same charge as of electrons but mass 208 times that of electrons). No deflection condition in this case satisfied if [Orissa (Engg.) 2002]
A)
B is increased 208 times done
clear
B)
E is increased 208 times done
clear
C)
B is increased 14.4 times done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer45)
The colour of the positive column in a gas discharge tube depends on [Kerala (Engg.) 2002]
A)
The type of glass used to construct the tube done
clear
B)
The gas in the tube done
clear
C)
The applied voltage done
clear
D)
The material of the cathode done
clear
View Solution play_arrow
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question_answer46)
Cathode rays are produced when the pressure is of the order of [Kerala (Engg.) 2002]
A)
2 cm of Hg done
clear
B)
0.1 cm of Hg done
clear
C)
0.01 mm of Hg done
clear
D)
1 \[\mu m\] of Hg done
clear
View Solution play_arrow
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question_answer47)
The speed of an electron having a wavelength of \[{{10}^{-10}}\,m\] is [AIIMS 2002]
A)
\[7.25\times {{10}^{6}}\,m/s\] done
clear
B)
\[6.26\times {{10}^{6}}\,m/s\] done
clear
C)
\[5.25\times {{10}^{6}}\,m/s\] done
clear
D)
\[4.24\times {{10}^{6}}\,m/s\] done
clear
View Solution play_arrow
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question_answer48)
Which of the following is not the property of a cathode ray [CBSE PMT 2002]
A)
It casts shadow done
clear
B)
It produces heating effect done
clear
C)
It produces flurosence done
clear
D)
It does not deflect in electric field done
clear
View Solution play_arrow
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question_answer49)
In a Thomson set-up for the determination of e/m, electrons accelerated by 2.5 \[kV\] enter the region of crossed electric and magnetic fields of strengths \[3.6\times {{10}^{4}}V{{m}^{-1}}\] and \[1.2\times {{10}^{-3}}T\] respectively and go through undeflected. The measured value of \[e/m\] of the electron is equal to [AMU 2002]
A)
\[1.0\times {{10}^{11}}C\text{-}k{{g}^{-1}}\] done
clear
B)
\[1.76\times {{10}^{11}}C\text{-}k{{g}^{-1}}\] done
clear
C)
\[1.80\times {{10}^{11}}C\text{-}k{{g}^{-1}}\] done
clear
D)
\[1.85\times {{10}^{11}}C\text{-}k{{g}^{-1}}\] done
clear
View Solution play_arrow
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question_answer50)
The ratio of specific charge of an \[\alpha \]-particle to that of a proton is [BCECE 2003]
A)
2 : 1 done
clear
B)
1 : 1 done
clear
C)
1 : 2 done
clear
D)
1 : 3 done
clear
View Solution play_arrow
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question_answer51)
In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field in B = 1T. The velocity of undeflected positive ions in m/s from the velocity selector is [RPMT 1998]
A)
\[{{10}^{7}}m/s\] done
clear
B)
\[{{10}^{4}}m/s\] done
clear
C)
\[{{10}^{5}}m/s\] done
clear
D)
\[{{10}^{2}}m/s\] done
clear
View Solution play_arrow
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question_answer52)
When cathode rays (tube voltage ~ 10 kV) collide with the anode of high atomic weight then we get [MP PET 1985]
A)
Positive rays done
clear
B)
X-rays done
clear
C)
Gamma rays done
clear
D)
Canal rays done
clear
View Solution play_arrow
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question_answer53)
In Thomson's experiment if the value of q/m is the same for all positive ions striking the photographic plate, then the trace would be [RPMT 1986]
A)
Straight line done
clear
B)
Parabolic done
clear
C)
Circular done
clear
D)
Elliptical done
clear
View Solution play_arrow
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question_answer54)
In a discharge tube at 0.02 mm, there is a formation of [CBSE PMT 1996]
A)
FDS done
clear
B)
CDS done
clear
C)
Both space done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer55)
Electric field and magnetic field in Thomson mass spectrograph are applied [RPMT 1998]
A)
Simultaneously, perpendicular done
clear
B)
Perpendicular but not simultaneously done
clear
C)
Parallel but not simultaneously done
clear
D)
Parallel simultaneously done
clear
View Solution play_arrow
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question_answer56)
The current conduction in a discharged tube is due to [CBSE PMT 1999]
A)
Electrons only done
clear
B)
+ve ions and electrons done
clear
C)
? ve ions and electrons done
clear
D)
+ ve ions, ? ve ions and electrons done
clear
View Solution play_arrow
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question_answer57)
In Milikan's oil drop experiment, a charged drop falls with terminal velocity V. If an electric field E is applied in vertically upward direction then it starts moving in upward direction with terminal velocity 2V. If magnitude of electric field is decreased to \[\frac{E}{2}\], then terminal velocity will become [CBSE PMT 1999]
A)
\[\frac{V}{2}\] done
clear
B)
V done
clear
C)
\[\frac{3V}{2}\] done
clear
D)
2V done
clear
View Solution play_arrow
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question_answer58)
An electron is accelerated through a p.d. of 45.5 volt. The velocity acquired by it is (in ms-1) [AIIMS 2004]
A)
\[4\times {{10}^{6}}\] done
clear
B)
\[4\times {{10}^{4}}\] done
clear
C)
\[{{10}^{6}}\] done
clear
D)
Zero done
clear
View Solution play_arrow
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question_answer59)
A cathode emits \[1.8\times {{10}^{14}}\] electrons per second, when heated. When 400V is applied to anode all the emitted electrons reach the anode. The charge on electron is \[1.6\times {{10}^{-19}}C\]. The maximum anode current is [MP PMT 2004]
A)
\[2.7\mu A\] done
clear
B)
\[29\mu A\] done
clear
C)
\[72\mu A\] done
clear
D)
29 mA done
clear
View Solution play_arrow
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question_answer60)
Order of q/m ratio of proton, \[\alpha \]-particle and electron is [AFMC 2004]
A)
\[e>p>\alpha \] done
clear
B)
\[p>\alpha >e\] done
clear
C)
\[e>\alpha >p\] done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer61)
A charge of magnitude \[3e\] and mass \[2m\] is moving in an electric field \[\overrightarrow{E}.\] The acceleration imparted to the charge is [DCE 2004]
A)
\[2Ee/3m\] done
clear
B)
\[3Ee/2m\] done
clear
C)
\[2m/3Ee\] done
clear
D)
\[3m/2Ee\] done
clear
View Solution play_arrow
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question_answer62)
An electron initially at rest, is accelerated through a potential difference of 200 volt, so that it acquires a velocity \[8.4\times {{10}^{6}}m/s.\] The value of e/m of electron will be [DPMT 2003]
A)
\[2.76\times {{10}^{12}}C/kg\] done
clear
B)
\[1.76\times {{10}^{11}}C/kg\] done
clear
C)
\[0.76\times {{10}^{12}}C/kg\] done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer63)
An a particle is accelerated through a p.d of \[{{10}^{6}}\] volt then K.E. of particle will be [Pb. PET 2003]
A)
8 MeV done
clear
B)
4 MeV done
clear
C)
2 MeV done
clear
D)
1 MeV done
clear
View Solution play_arrow
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question_answer64)
Positive rays consists of [RPMT 1996, 2003]
A)
Electrons done
clear
B)
Neutrons done
clear
C)
Positive ions done
clear
D)
Electromagnetic waves done
clear
View Solution play_arrow
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question_answer65)
\[{{O}^{++}},\ {{C}^{+}},\ H{{e}^{++}}\] and \[{{H}^{+}}\] ions are projected on the photographic plate with same velocity in a mass spectrograph. Which one will strike farthest [RPMT 2003]
A)
\[{{O}^{++}}\] done
clear
B)
\[{{C}^{+}}\] done
clear
C)
\[H{{e}^{++}}\] done
clear
D)
\[H_{2}^{+}\] done
clear
View Solution play_arrow
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question_answer66)
An electron beam is moving between two parallel plates having electric field \[1.125\times {{10}^{-6}}N/m\]. A magnetic field \[3\times {{10}^{-10}}T\] is also applied so that beam of electrons do not deflect. The velocity of the electron is [MH CHT 2004]
A)
\[4225\ m/s\] done
clear
B)
\[3750\ m/s\] done
clear
C)
\[2750\ m/s\] done
clear
D)
\[3200\ m/s\] done
clear
View Solution play_arrow
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question_answer67)
Positive rays was discovered by [RPMT 1998]
A)
Thomson done
clear
B)
Goldstem done
clear
C)
W. Crookes done
clear
D)
Rutherford done
clear
View Solution play_arrow
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question_answer68)
An electron is moving in electric field and magnetic field it will gain energy from [DCE 1998]
A)
Electric field done
clear
B)
Magnetic field done
clear
C)
Both of these done
clear
D)
None of these done
clear
View Solution play_arrow
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question_answer69)
If an electron oscillates at a frequency of 1 GHz it gives [DCE 1999]
A)
X-rays done
clear
B)
Mirowaves done
clear
C)
Infrared rays done
clear
D)
None of these done
clear
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question_answer70)
In an electron gun, the electrons are accelerated by the potential V. If e is the charge and m is the mass of an electron, then the maximum velocity of these electrons will be [MP PMT 1987, 96; BHU 1995; MNR 1998]
A)
\[\frac{2eV}{m}\] done
clear
B)
\[\sqrt{\frac{2eV}{m}}\] done
clear
C)
\[\sqrt{\frac{2m}{eV}}\] done
clear
D)
\[\frac{{{V}^{2}}}{2em}\] done
clear
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question_answer71)
Which of the following have highest specific charge [BHU 2005]
A)
Positron done
clear
B)
Proton done
clear
C)
He done
clear
D)
None of these done
clear
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question_answer72)
In Millikan?s oil drop experiment, an oil drop of mass \[16\times {{10}^{-6}}kg\] is balanced by an electric field of \[{{10}^{6}}V/m.\] The charge in coulomb on the drop, assuming \[g=10\,m/{{s}^{2}}\] is [UP SEAT 2005]
A)
\[6.2\times {{10}^{-11}}\] done
clear
B)
\[16\times {{10}^{-9}}\] done
clear
C)
\[16\times {{10}^{-11}}\] done
clear
D)
\[16\times {{10}^{-13}}\] done
clear
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