JEE Main Electromagnetism — practice questions
120 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice JEE Main Electromagnetism in the app →If charge is defined as the deficiency or excess of electrons on a body, which situation will make a neutral bWhat is meant by static electricity?Which pair of charges will attract each other?Two bodies carrying like charges are brought near each other. What happens?Which statement about electric charge is correct?A body has an excess of electrons. What kind of net charge does it possess?Which statement about the force between two charges is correct according to the given law?Two point charges exert a force $F$ on each other. If each charge is halved and the distance is also halved, tWhich change will leave the electrostatic force between two point charges unchanged according to $F = k\dfrac{An isolated system contains charges $+5\,\text{C}$ and $-5\,\text{C}$. If they are brought together, which staIf both charges are doubled and the separation between them is kept unchanged, the electrostatic force becomesTwo charges are moved so that the distance between them becomes three times the original value. The new electrIf $q_1 = q_2 = 1\,\text{C}$ and $r = 1\,\text{m}$ in the relation $F = k\dfrac{q_1 q_2}{r^2}$, then the magniIn the given expression $F = k\dfrac{q_1 q_2}{r^2}$, what does the constant $k$ represent in this content?Which formula matches the form of Coulomb's law given in the notes for two charges $q_1$ and $q_2$ separated bThe dependence of electrostatic force on separation between two point charges is best described asTwo point charges are separated by a distance $r$. If one charge is doubled and the other remains unchanged, tIf the distance between two point charges is doubled while the charges remain unchanged, the electrostatic forAccording to Coulomb's law, the electrostatic force between two point charges is directly proportional toWhich statement correctly expresses the principle of conservation of electric charge?Two point charges of $+4\ \mu$C each are separated by $0.6$ m in vacuum. The magnitude of the electrostatic foWhat is the electric field at the centre of a hollow conducting sphere of radius $R$ carrying total charge $Q$A parallel-plate capacitor has capacitance $C_0$ in vacuum. A dielectric slab of dielectric constant $K = 4$ iTwo capacitors of $6\ \mu$F and $3\ \mu$F are connected in series across a $12$ V battery. What is the equivalAn electric dipole of moment $p$ is placed at $60°$ to a uniform electric field of magnitude $E$. The torque oA point charge $+q$ is placed at the centre of a cube. What is the electric flux through one face of the cube?
Oersted's experiment demonstrated that:The magnetic field at a perpendicular distance $r$ from a long straight current-carrying wire of current $I$ iA circular coil of radius $R$ carries current $I$. The magnetic field at the centre of the coil is:Two long, parallel wires carry currents $I_1$ and $I_2$ in the **same direction** separated by distance $d$. TA charged particle moves perpendicular to a uniform magnetic field $B$ with speed $v$. The radius of its circuThe SI unit of electric charge is the:Coulomb's law: force between two point charges is proportional to:The value of k in Coulomb's law (in SI) is approximately:Electric field strength at a point is defined as force per unit:Total electric flux through a closed surface enclosing charge q (Gauss's law) is:Electric field due to an INFINITE SHEET of charge with surface charge density σ:The principle that charge can be neither created nor destroyed is:Two point charges +2μC and -3μC are separated by 30 cm. The force on each (k = 9 × 10⁹):Electric field due to a point charge q at distance r:A charge of 1 C placed in an electric field of 100 N/C experiences force:Electric potential V due to point charge q at distance r:Potential difference between two points is 12 V. Work done to move 2 C between them:Electric field INSIDE a conductor in electrostatic equilibrium is:At an axial point of an electric dipole at distance r >> a (a = dipole half-length, p = qa·2 the dipole momentNumber of charges that can be enclosed in a Gaussian surface in vacuum:For a parallel plate capacitor with plate area A and separation d, the capacitance in vacuum:Capacitance changes when DIELECTRIC of relative permittivity K is inserted:Energy stored in a capacitor with charge Q and capacitance C:Two charges +q and +q are placed at corners of an equilateral triangle. The third corner has potential:For a spherical conductor of radius R carrying charge Q, the potential AT THE SURFACE equals:Equipotential surfaces around a point charge are:Two capacitors 2 µF and 4 µF connected in SERIES across 12 V. Charge on each:3 capacitors of 6 µF each in PARALLEL: total capacitance:Two charged spheres each of radius R, charge Q, separated by distance d >> R. Force F between them is:Potential at center of square (side a) with charges +q, -q, +q, -q at corners (alternating):Electric field inside a spherical cavity in a uniformly charged conductor is:Find work done to bring a +2 µC charge from infinity to a point where V = 50 V:A charged particle q is held at rest in vertical equilibrium in a uniform electric field E pointing upward. ChIn a capacitor circuit, when a dielectric is inserted while voltage is HELD CONSTANT by battery, the CHARGE onMagnetic field is measured in:Biot Savart law gives magnetic field due to a current element. It states dB is proportional to:The magnetic force on a charge q moving with velocity v in field B:A current-carrying wire of length L in magnetic field B experiences force:Ampere's law states the line integral of B around a closed loop equals:A magnetic dipole moment of a current loop is:Magnetic field at center of a circular loop of radius R carrying current I:Magnetic field inside a long solenoid (n turns per unit length, current I):Magnetic field at distance r from a long straight current-carrying wire:A charged particle of charge q, mass m enters magnetic field B perpendicular to velocity v. It follows a:Two parallel wires 1 m apart carry currents I1 = 2 A and I2 = 3 A in the SAME direction. Force per unit lengthTorque on a current loop (moment m) in uniform field B:In a velocity selector, electric field E and magnetic field B are perpendicular. Velocity of particles passingMagnetic field on the axis of a circular loop at distance x from center:Magnetic flux through a surface is:A proton (mass m, charge e) enters a uniform magnetic field B perpendicular to its velocity v. Time to completCyclotron frequency for a charged particle in magnetic field B:An electron beam moves with velocity v in a region with E perpendicular to v. To pass undeflected, magnetic fiA solenoid of 200 turns, length 0.5 m, carries 2 A. Find magnetic field inside (μ₀ = 4π × 10⁻⁷):A charged particle moves in a circle of radius 2 cm in a 1 T magnetic field with speed 4 × 10⁶ m/s. Mass-to-chIn a hydrogen atom, the magnetic moment associated with electron orbital motion in ground state is approximateFor a current loop in a non-uniform magnetic field, net force is zero only if:Earth's magnetic field is approximately 50 μT. Force on a 1 m wire carrying 10 A perpendicular to field:A toroid with 1000 turns and average radius 10 cm carries 0.5 A current. Field inside:A solenoid is also called an 'electromagnet'. Why does inserting an iron core greatly increase its magnetic fiTwo parallel wires carrying currents in OPPOSITE directions:A magnetic dipole of moment m in field B has potential energy:In a mass spectrometer, ions of same charge but different mass enter perpendicular to uniform B with same veloA proton moves north at $10^6$ m/s in a magnetic field of $0.1$ T pointing east. The magnetic force on it is:A long straight wire carries $5$ A. The magnetic field $0.10$ m away from the wire is:A solenoid has $500$ turns per metre and carries $2$ A. Field inside is:The cyclotron frequency of a particle of mass $m$ and charge $q$ in field $B$ is:Coulomb's law gives the force between two point charges q₁ and q₂ separated by distance r in vacuum asTwo point charges of +2 μC each are placed 3 m apart in vacuum. The force between them is (k = 9 × 10⁹ N m²/C²The electric field at distance r from an isolated point charge q isThe electric field of an infinite line of charge with linear charge density λ at perpendicular distance r isThe electric field just outside a uniformly charged infinite plane with surface charge density σ isGauss's law states that the total electric flux through a closed surface equalsAn electric dipole consists of two equal and opposite point charges ±q separated by distance 2a. Its dipole moThe electric field on the axial line of a short electric dipole at distance r isAn electric dipole in a uniform electric field E experiencesThe principle of quantisation of electric charge is stated asTwo charges +q and −q of equal magnitude are placed at the corners A and B of an equilateral triangle. The netThe electric flux through a closed surface enclosing a charge of +5 μC is (ε₀ = 8.85 × 10⁻¹² C²/N m²)For a charge distribution with volume density ρ, the total charge Q equalsThe SI unit of electric field isIf a positive point charge is placed at the centre of a spherical conducting shell of radius R (neutral), the Electromagnetic induction was demonstrated by Michael Faraday and:Michael Faraday carried out his experiments in:Joseph Henry carried out his experiments in:Their experiments were conducted around the year:Currents are induced in closed coils by changing:Generating current by varying magnetic fields is called electromagnetic:Asked what use his discovery was, Faraday compared it to a:The SI unit of magnetic flux is the:One weber is the same as one:Magnetic flux is which kind of quantity?Faraday's law says an emf is induced when the flux does what with time?Lenz deduced his rule in the year:Heinrich Friedrich Lenz was a physicist from: