Description : The concept of electric field theory was introduced by: (a) Kepler (b) Newton (c) Dalton (d) Michael Faraday
Last Answer : (d) Michael Faraday
Description : Michael Faraday was known by his work on: (a) Electric force (b) Weak nuclear force (c) Strong nuclear force (d) Gravitational force
Last Answer : (a) Electric force
Description : Maxwell second equation is based on which law? a) Ampere law b) Faraday law c) Lenz law d) Coulomb law
Last Answer : a) Ampere law
Description : The first Maxwell law is based on which law? a) Ampere law b) Faraday law c) Lenz law d) Faraday and Lenz law
Last Answer : b) Faraday law
Description : The induced emf in a material opposes the flux producing it. This is a) Faraday law b) Ampere law c) Lenz law d) Curie law
Last Answer : c) Lenz law
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 : 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 : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field
Last Answer : d. gravitational 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 : The space around the charge within which other charges are influenced by it is called: (a) Electric field (b) Magnetic field (c) Electric flux (d) Electric intensity
Last Answer : a) Electric field
Description : Biot Savart law in magnetic field is analogous to which law in electric field? a) Gauss law b) Faraday law c) Coulomb’s law d) Ampere law
Last Answer : c) Coulomb’s law
Description : Whenmicrowave signalsfollowthe curvatureofthe earth,thisisknownas a. the Faraday effect b.ducting c. tropospheric scatter d. ionospheric reflection
Last Answer : b.ducting
Description : Distancesnearthe skip distance should beused forthe sky-wave propagation a. to avoid tilting b.topreventsky-wave andupper rayinterference c. to avoid the Faraday effect d. so as nor to exceed the critical frequency
Last Answer : b.topreventsky-wave andupper rayinterference
Description : Indicatewhich one ofthe followingterms appliestotroposcatter propagation: a. SIDs b.Fading c. Atmospheric storms d. Faraday rotation
Last Answer : b.Fading
Description : The phenomena of induced emf was observed by Faraday and Henry in: a. 1931 b. 1831 c. 1535 d. 1940
Last Answer : a. 1931
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 : 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 : 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 : 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 : 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 : ___________ 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 : If PN junction is forward biased its resistance is (a) Zero (b) Infinity (c) A few ohm (d) A few kilo ohms
Last Answer : c) A few ohm
Description : The unit of inductance is: a. Volt b. Ampere c. Henry d. Ohm
Last Answer : c. Henry
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 : SI unit of resistivity is a. ohm b. Ohm×m c. Ohm×m-1 d. Ohm×m2
Last Answer : c. Ohm×m-1
Description : Resistance between points A and B in the circuit shown in figure is a. 4 ohm b. 6ohm c. 10 ohm d. 8 ohm
Last Answer : c. 10 ohm
Description : The deflection system of a TV picture tube makes use of a) magnetic deflection b) electric deflection c) Both (a) and (b) d) None of these
Last Answer : a) magnetic deflection
Description : The magnetic materials follow which law? a) Faraday’s law b) Ampere law c) Lenz law d) Curie Weiss law
Last Answer : d) Curie Weiss law
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 : 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 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 : 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 : 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 : 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 : 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 : 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 : The magnetic field is _________ inside a solenoid a) Zero b) uniform c) non-uniform d) infinite
Last Answer : b) uniform
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 : 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 : 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 magnetic screw placed in a non-uniform magnetic field experiences a) force and torque b) only torque c) only force d) None of these
Last Answer : a) force and torque
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 : 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 : 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