Description : A magnetic needle is kept in a non-uniform management field. It experiences (a) A force and a torque (b) A force but not a torque (c) A torque but not a force (d) Neither a force nor a torque
Last Answer : Ans:(a)
Description : iv) A rectangular coil free to rotate is placed in uniform magnetic field with its plane parallel to the magnetic lines of force. Then the coil willa) rotate to maximize the magnetic flux through ... since the magnetic flux through its plane is zero.d) experience the constant torque equal to NBIA
Last Answer : iv) A rectangular coil free to rotate is placed in uniform magnetic field with its plane parallel ... d) experience the constant torque equal to NBIA
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 : 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 conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be (a) zero (b) BLI (c) B2LI (d) BLI2
Last Answer : (a) zero
Description : When an iron piece is placed in a magnetic field (a) the magnetic lines of force will bend away from their usual paths in order to go away from the piece (b) the magnetic lines of force will bend ... to pass through the piece (c) the magnetic field will not be affected (d) the iron piece will break
Last Answer : (b) the magnetic lines of force will bend away from their usual paths in order to pass through the piece
Description : The magnetic field is _________ inside a solenoid a) Zero b) uniform c) non-uniform d) infinite
Last Answer : b) uniform
Description : The pole faces of U-shaped magnet in a moving coil galvanometer are made concave to a) decrease the strength of magnetic field b) create a non-uniform magnetic field c) make the magnetic field radial d) All of these
Last Answer : c) make the magnetic field radial
Description : Assertion Net torque in the current carrying loop placed in a uniform magnetic field (pointing inwards) is zero. Reasonl Magnetic moment (M) is inward
Last Answer : Assertion Net torque in the current carrying loop placed in a uniform magnetic field (pointing inwards) ... . Reasonl Magnetic moment (M) is inwards.
Description : A circular coil of `20turns` and radius `10cm` carries a current of `5A`. It is placed in a uniform magnetic field of `0*10T`. Find the torque acting
Last Answer : A circular coil of `20turns` and radius `10cm` carries a current of `5A`. It is placed in a uniform magnetic ... Nm B. 3.14 Nm C. 0.314 Nm D. zero
Description : A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon
Last Answer : A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not ... turns in the loop D. strength of the current
Description : A wire loop is moved parallel to a uniform magnetic field. The induced emf in the loop: a. depends on the shape b. depends on area c. depends on nature of loop d. zero
Last Answer : d. zero
Description : When a uniform magnetic field B is applied to a current carrying coil, the coil will rotate in such a manner that its plane a) becomes parallel to B b) becomes anti-parallel to B c) makes an angle of 600 with B d) becomes perpendicular to B
Last Answer : d) becomes perpendicular to B
Description : The magnetic flux φB through a plane element of area A⃗ in a uniform magnetic field B⃗⃗ is minimum at a) θ = 900 b) θ = 00 c) θ = 1800 d) None of these
Last Answer : a) θ = 900
Description : A proton and a α particle enter a region having a perpendicular uniform magnetic field. The ratio of time period of proton (τp) to time period of α particle (τα) is a) 1:4 b) 4:1 c) 2:1 d) 1:2
Last Answer : d) 1:2
Description : Work done by a uniform magnetic field in moving a charged particle in a circular path is a) qvB sin θ b) mg sin θ c) zero d) mg cos θ
Last Answer : Zero
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 : State the expression for the magnetic force on straight current carrying conductor placed in uniform magnetic field
Last Answer : State the expression for the magnetic force on straight current carrying conductor placed in uniform magnetic field
Description : A current of `10` ampere is flowing in a wire of length `1.5m`. A force of `15 N` acts on it when it is placed in a uniform magnetic field of `2` tesl
Last Answer : A current of `10` ampere is flowing in a wire of length `1.5m`. A force of `15 N` acts on it when it is placed ... `45^(@)` C. `60^(@)` D. `90^(@)`
Description : The left hand rule correlates to (a) current, induced e.m.f. and direction of force on a conductor (b) magnetic field, electric field and direction of force on a conductor (c) self induction, ... and direction of force on a conductor (d) current, magnetic field and direction of force on a conductor
Last Answer : (d) current, magnetic field and direction of force on a conductor
Description : Fleming's left hand rule is used to find (a) direction of magnetic field due to current carrying conductor (b) direction of flux in a solenoid (c) direction of force on a current carrying conductor in a magnetic field (d) polarity of a magnetic pole
Last Answer : (c) direction of force on a current carrying conductor in a magnetic field
Description : When the field is strong, the lines of force are: (a) Closer (b) Parallel (c) Farther (d) All of above 45. The electric lines of force determine the strength of an: (a) Gravitational field (b) Constant field (c) Magnetic field (d) Electric field
Last Answer : d) Electric field
Description : In case of two identical charges placed at certain distance, the electric lines of force are: (a) Curved (b) Straight lines (c) Both (a) and (b) (d) None of these
Last Answer : a) Curved
Description : The electric force between two charges placed in air is 2 Newton. When placed in a medium of ∈r = 80, the force reduced to: (a) 0.029 N (b) 0.025 N (c) 0.03 N (d) 0.04 N
Last Answer : (b) 0.025 N
Description : Assertion In non-uniform magnetic field speed of a charged particle varies. Reason Work done by magnetic force on a charged particle is always zero.
Last Answer : Assertion In non-uniform magnetic field speed of a charged particle varies. Reason Work done by ... If Assertion is false but Reason is true.
Description : A conducting loop is placed in a uniform magnetic field with its plane perpendicular to the field with its plane perpendicular to the field. An emf is
Last Answer : A conducting loop is placed in a uniform magnetic field with its plane perpendicular to the field ... . the loop is deformed from the original shape
Description : Assertion A flexeble wire loop of irregular shape carrying current when placed in a uniform external magnetic field acquires a circular shape. Reason
Last Answer : Assertion A flexeble wire loop of irregular shape carrying current when placed in a uniform external ... circular shape is having the greatert area.
Description : A circular flexible loop of wire of radius r carrying a current I is placed in a uniform magnetic field B . If B is doubled, then tension in the loop
Last Answer : A circular flexible loop of wire of radius r carrying a current I is placed in a uniform magnetic field ... is doubled C. is halved D. becomes 4 times
Description : A conducting loop carrying a current `I` is placed in a uniform magnetic field ponting into the plane of the paper as shown. The loop will have a tend
Last Answer : A conducting loop carrying a current `I` is placed in a uniform magnetic field ponting into the plane of the ... +ve X-axis D. move towards -ve X-axis
Description : The direction of magnetic lines of force is (a) from south pole to north pole (b) from north pole to south pole (c) from one end of the magnet to another (d) none of the above
Last Answer : (b) from north pole to south pole
Description : A permeable substance is one (a) which is a good conductor (6) which is a bad conductor (c) which is a strong magnet (d) through which the magnetic lines of force can pass very easily
Last Answer : (d) through which the magnetic lines of force can pass very easily
Description : The expression F⃗ = qE⃗⃗ + q(v⃗ × B⃗⃗) represents _________ force a) Maxwell b) Gravitational c) Magnetic d) Lorentz
Last Answer : d) Lorentz
Description : A material which is slightly repelled by a magnetic field is known as (a) ferromagnetic material (b) diamagnetic material (c) paramagnetic material (d) conducting material
Last Answer : (b) diamagnetic material
Description : Which of the following is a vector quantity ? (a) Relative permeability (b) Magnetic field intensity (c) Flux density (d) Magnetic potential
Last Answer : (b) Magnetic field intensity
Description : A magnetic field exists around (a) iron (b) copper (c) aluminium (d) moving charges
Last Answer : (d) moving charges
Description : The windings of the electromagnetic are usually called: a. Magnetic coils b. Field coil c. Electric coil d. simple coil
Last Answer : c. Electric coil
Description : The induced emf in a coil depends upon: a. Strength of magnetic field b. Resistance of the coil c. area of the coil d. All of them
Last Answer : d. All of them
Description : The induced current can be increased by: a. Using strong magnetic field b. moving loop faster c. Replacing loop by coil d. all of above
Last Answer : d. all of above
Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field
Last Answer : d. gravitational field
Description : A magnetic field acts on a charged particles so as to change its: a. speed b. energy c. direction of motion d. all of these
Last Answer : Only direction of motion will change ...it means velocity will change but speed same
Description : If magnetic field is doubled then magnetic energy density becomes: a. Four times b. Two times c. Three times d. Six times
Last Answer : c. Three times
Description : Electric current produces magnetic field was suggested by: a. Faraday b. Lenz c. Ohm d. Oerested
Last Answer : c. Ohm
Description : If velocity of a conductor moving through a magnetic field ‘B’ is made zero, then Motional emf will be: a. –VBL b. –V/BL c. – BL/V d. zero
Last Answer : a. –VBL
Description : A proton and a deuteron have same kinetic energies while moving in a perpendicular magnetic field. The following gives the ratio of radii of their circular paths a) √2 : 1 b) 1: √2 c) 1:4 d) 1:1
Last Answer : b) 1: √2
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 : A solenoid has n turns and length l. If length is reduced to l/2 and turns are doubled then magnetic field B produced by it becomes equal to a) 2B b) 4B c) 1/2 B d) None of these
Last Answer : a) 2B
Description : A proton having mass m and charge q is projected into a region having a perpendicular magnetic field. The angle of deviation of proton when it comes out of the region with mv √2 qB ⁄ is a) π/3 b) π/4 c) π/6 d) 2 π/3
Last Answer : b) π/4
Description : ___________ remain undeflected in a magnetic field a) β particles b) α particles c) γ rays d) Proton beams
Last Answer : c) γ rays
Description : Which of the following quantities change when a proton moves at right angles to a magnetic field? a) Momentum b) Energy c) Speed d) All of these
Last Answer : a) Momentum
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