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The magnetic force acting on a charged particleof charge – 2μC in a magnetic field of 2T actingin y direction, when the particle velocity is , is
Under the influence of a uniform magnetic field,a charged particle moves with constant speed vin a circle of radius R. The time period of rotationof the particle: [2009]
A thin ring of radius R meter has charge q coulomb uniformly spread on it. The ring rotates about its axis with a constant frequency of f revolutions/s. The value of magnetic induction in Wb/m^{2} at the centre of the ring is [2010]
A galvanometer has a coil of resistance 100 ohmand gives a fullscale deflection for 30 mAcurrent. It is to work as a voltmeter of 30 voltrange, the resistance required to be added willbe [2010]
A square current carrying loop is suspended in a uniform magnetic field acting in the plane of the loop. If the force on one arm of the loop is , the net force on the remaining three arms of the loop is
A particle having a mass of 10^{–2} kg carries a charge of 5 × 10–^{8 }C. The particle is given an initial horozontal velocity of 10^{5} ms^{–1} in the presence of electric field and magnetic field . To keep the particle moving in a horizontal direction, it is necessary that
(1) should be perpendicular to the direction of velocity and should be along the direction of velocity.
(2) Both and should be along the direction of velocity.
(3) Both and are mutually perpendicular and perpendicular to the direction of velocity.
(4) should be along the direction of velocity and should be perpendicular to the direction of velocity
Which one of the following pairs of statements is possible?
A closely wound solenoid of 2000 turns and areaof crosssection 1.5 × 10^{–4} m^{2} carries a currentof 2.0 A. It suspended through its centre andperpendicular to its length, allowing it to turn ina horizontal plane in a uniform magnetic field 5 ×10^{–2} tesla making an angle of 30° with the axis ofthe solenoid. The torque on the solenoid will be:
A current loop consists of two identical semicircular parts each of radius R, one lying in the xy plane and the other in xz plane. If the current in the loop is i., the resultant magnetic field due to the two semicircular parts at their common centre is
A current carrying loop in the form of a right angle isosceles triangle ABC is placed in a uniform magnetic field acting along AB. If the magnetic force on the arm BC is F, what is the force on the arm AC?
A uniform electric field and uniform magneticfield are acting along the same direction in acertain region. If an electron is projected in theregion such that its velocity is pointed alongthe direction of fields, then the electron [2011]
A galvanometer of resistance, G is shunted by a resistance S ohm. To keep the main current in the circuit unchanged, the resistance to be put in series with the galvanometer is [2011M]
A square loop, carrying a steady current I, is placed in a horizontal plane near a long straight conductor carrying a steady current I_{1} at a distance d from the conductor as shown in figure. The loop will experience [2011M]
Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency f Hz. The magnitude of magnetic induction at the centre of the ring is [2011M]
Two similar coils of radius R are lying concentrically with their planes at right angles to each other. The currents flowing in them are
I and 2 I, respectively. The resultant magnetic field induction at the centre will be: [2012]
An alternating electric field, of frequency v, is applied across the dees (radius = R) of a cyclotron that is being used to accelerate
protons (mass = m). The operating magnetic field (B) used in the cyclotron and the kinetic energy (K) of the proton beam, produced by it, are given by : [2012]
An αparticle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m^{2}. The deBroglie wavelengthassociated with the particle will be : [2012]
A proton carrying 1 MeV kinetic energy ismoving in a circular path of radius R in uniformmagnetic field. What should be the energy of an α particle to describe a circle of same radius inthe same field? [2012M]
A current loop in a magnetic field [NEET 2013]
When a proton is released from rest in a room, it starts with an initial acceleration a_{0} towards west. When it is projected towards north with a speed v_{0} it moves with an initial acceleration 3a0 towards west. The electric and magnetic fields in the room are respectively [NEET 2013]
A long straight wire carries a certain current and produces a magnetic field of at a perpendicular distance of 5 cm from the wire. An electron situated at 5 cm from the wire moves with a velocity 10^{7} m/s towards the wire along perpendicular to it. The force experienced by the electron will be
(charge on electron =1.6 × 10^{–19} C)
When a proton is accelerated through 1 V, thenits kinetic energy will be [1999]
If a long hollow copper pipe carries a current,then magnetic field is produced [1999]
Two long parallel wires P and Q are both perpendicular to the plane of the paper with distance of 5 m between them. If P and Q carry currents of 2.5 amp and 5 amp respectively in the same direction, then the magnetic field at a point halfway between the wires is [2000]
A proton moving with a velocity 3 × 10^{5} m/senters a magnetic field of 0.3 tesla at an angle of30º with the field. The radius of curvature of itspath will be (e/m for proton = 108 C/kg) [2000]
In a certain region of space electric field and magnetic field are perpendicular to each other and an electron enters in region perpendicular to the direction of and both and moves undeflected, then velocity of electron is [2001]
A charged particle of charge q and mass m enters perpendicularly in a magnetic field . Kinetic energy of the particle is E; then frequency of rotation is [2001]
A galvanometer can be converted into avoltmeter by connecting [2002]
A wire carries a current. Maintaining the samecurrent it is bent first to form a circular plane coil ofone turn which produces a magnetic field B at thecentre of the coil. The same length is now bentmore sharply to give a double loop of smaller radius.The magnetic field at the centre of the double loop,caused by the same current is [2002]
A particle having charge q moves with a velocity through a region in which both an electric field and a magnetic field are present .The force on the particle is [2002]
A charged particle moves through a magneticfield in a direction perpendicular to it. Then the [2003]
A long solenoid carrying a current produces amagnetic field B along its axis. If the current isdouble and the number of turns per cm is halved,the new value of the magnetic field is [2003]
A galvanometer acting as a voltmeter will have [2004]
A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 × 10^{–4} ampere gives adeflection of one per division. To convert thisgalvanometer into a voltmeter having a rangeof 25 volts, it should be connected with aresistance of [2004]
An electron moves in a circular orbit with a uniform speed v. It produces a magnetic field B at the centre of the circle. The radius of the circle is proportional to [2005]
A very long straight wire carries a current I. At the instant when a charge + Q at point P has velocity , as shown, the force on the charge is
When a charged particle moving with velocity is subjected to a magnetic field of induction the force on it is nonzero. This implies that
Two circular coils 1 and 2 are made from the samewire but the radius of the 1st coil is twice that ofthe 2nd coil. What potential difference in voltsshould be applied across them so that themagnetic field at their centres is the same [2006]
A beam of electron passes undeflected throughmutually perpendicular electric and magnetic fields.If the electric field is switched off, and the samemagnetic field is maintained, the electrons move [2007]
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential V and then made to describe semicircular path of radius R using a magnetic field B. If V and B are kept constant, the ratio will be proportional to
Under the influence of a uniform magnetic fielda charged particle is moving in a circle of radiusR with constant speed v. The time period of themotion [2007]
A closed loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR, and RQ are F_{1} , F_{2} and F_{3} respectively and are in the plane of the paper and along the directions shown, the force on the segment QP is [2008]
A particle of mass m, charge Q and kinetic energyT enters a transverse uniform magnetic field ofinduction . After 3 seconds, the kinetic energyof the particle will be: [2008]
A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction in such a way that its axis makes an angle of 60° with . The magnetic flux linked with the disc is: [2008]
A galvanometer having a coil resistance of 60 Ωshows full scale deflection when a current of 1.0amp passes through it. It can be convertedinto an ammeter to read currents upto 5.0 amp by [2009]
A charged paritcle (charge q) is moving in a circleof radius R with uniform speed v. The associatedmagnetic moment μ is given by [2007]
A current carrying coil is subjected to a uniformmagnetic field. The coil will orient so that itsplane becomes [1988]
Tesla is the unit of [1988]
Energy in a current carrying coil is stored in theform of [1989]
The total charge induced in a conducting loopwhen it is moved in a magnetic field depends on [1990]
The magnetic induction at a point P which is at adistance of 4 cm from a long current carryingwire is 10^{–3} T. The field of induction at a distance12 cm from the current will be [1990]
A deuteron of kinetic energy 50 keV is describinga circular orbit of radius 0.5 metre in a planeperpendicular to the magnetic field B. The kineticenergy of the proton that describes a circularorbit of radius 0.5 metre in the same plane withthe same B is [1991]
A uniform magnetic field acts at right angles tothe direction of motion of electron. As a result,the electron moves in a circular path of radius2cm. If the speed of electron is doubled, thenthe radius of the circular path will be [1991]
The magnetic field at a distance r from a longwire carrying current i is 0.4 tesla. The magneticfield at a distance 2r is [1992]
A straight wire of length 0.5 m that is carrying a current of 1.2 A is placed in a uniform magnetic field of induction 2T, and the magnetic field is perpendicular to the length of the wire. What is the force of the wire?
To convert a galvanometer into an ammeter, oneneeds to connect a [1992]
A coil carrying electric current is placed inuniform magnetic field, then [1993]
A charge moving with velocity v in Xdirectionis subjected to a field of magnetic induction innegative Xdirection. As a result, the charge will [1993]
An electron enters a region where magnetic field(B) and electric field (E) are mutually perpendicular,then [1994]
A straight wire of diameter 0.5 mm carrying acurrent of 1 A is replaced by another wire of 1mm diameter carrying same current. The strengthof magnetic field far away is [1995, 97, 99]
At what distance from a long straight wirecarrying a current of 12 A will the magnetic fieldbe equal to 3×10^{6}Wb /m^{2} ? [1995]
The magnetic field due to a small element (dℓ ) at a distance and element carrying current i is [1996]
A 10 eV electron is circulating in a plane at rightangles to a uniform field at magnetic induction10^{– 4} Wb/m^{2} (= 1.0 gauss). The orbital radius ofthe electron is [1996]
Two equal electric currents are flowing perpendicular to each other as shown in the figure. AB and CD are perpendicular to each other and symmetrically placed with respect to the current flow. Where do we expect the resultant magnetic field to be zero? [1996]
A beam of electrons is moving with constantvelocity in a region having simultaneousperpendicular electric and magnetic fields ofstrength 20 Vm^{–1} and 0.5 T respectively at rightangles to the direction of motion of the electrons.Then the velocity of electrons must be [1996]
A galvanometer of resistance 20 Ω gives fullscale deflection with a current of 0.004 A. Toconvert it into an ammeter of range 1 A, therequired shunt resistance should be [1996]
A positively charged particle moving due eastenters a region of uniform magnetic field directedvertically upwards. The particle will [1997]
Two long parallel wires are at a distance of 1metre. Both of them carry one ampere of current.The force of attraction per unit length betweenthe two wires is [1998]
A galvanometer having a resistance of 8 ohmsis shunted by a wire of resistance 2 ohms. If thetotal current is 1 amp, the part of it passingthrough the shunt will be [1998]
A coil of one turn is made of a wire of certainlength and then from the same length a coil oftwo turns is made. If the same current is passedin both the cases, then the ratio of the magneticinductions at their centres will be [1998]
Magnetic field intensity at the centre of a coil of50 turns, radius 0.5 m and carrying a current of 2A is [1999]
157 videos453 docs185 tests

157 videos453 docs185 tests
