TS EAPCET (Engineering) Moving Charges and Magnetism — practice questions
103 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice TS EAPCET (Engineering) Moving Charges and Magnetism in the app →A circular coil of radius $R$ carries current $I$. The magnetic field at the centre of the coil is:Magnetic 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:Torque 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:Cyclotron frequency for a charged particle in magnetic field B:A 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-chFor 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:Two parallel wires carrying currents in OPPOSITE directions:A magnetic dipole of moment m in field B has potential energy:Oersted's 1820 demonstration showed a current deflecting which object?In which year did Oersted observe a current deflecting a compass needle?Oersted concluded that a magnetic field is produced by what?Which physicist realised that light is an electromagnetic wave after unifying electricity and magnetism?A charge moving parallel to a magnetic field feels what magnetic force?In which direction does the magnetic force on a moving charge act?One gauss, the smaller non-SI unit of magnetic field, equals how many tesla?Which combination of units is equivalent to one tesla?A 0.5 m wire carrying 4 A is at 30° to a 0.2 T field. Force on it?An electron moves at 2 × 10^6 m/s perpendicular to a 0.5 T field. Force on it?Why does a magnetic field do no work on a moving charge?If a charge's velocity has a component along B, its path isRadius of the circular path of charge q, mass m, speed v in field B isDoubling a charged particle's speed in a fixed field changes its orbit radius how?The frequency of circular motion of a charge in B is independent ofIf B doubles, how does the orbital frequency of a given charge change?What property of circular motion in B does a cyclotron exploit?The distance a helically moving charge advances along B in one rotation is called itsAn electron moving at 3 × 10^7 m/s has a kinetic energy of aboutIn the Biot-Savart law, the magnitude of dB varies with distance r asThe Biot-Savart law gives the magnetic field due to which source?The Biot-Savart field dB at a point along the line of the current element isWhich relation links μ0, ε0 and the speed of light c?How do the Coulomb and Biot-Savart fields both depend on distance?The Biot-Savart field dB at point P points in which direction?A single loop of radius 10 cm carries 5 A. Field at its centre?A long straight wire carries 10 A. What is the field 5 cm from it?Ampere's circuital law: loop integral of B equalsThe closed contour chosen when applying Ampere's law is called aIf the net current enclosed by an Amperian loop is zero, the line integral of B isThe field outside an ideal very long solenoid is taken to beInside a long solenoid the magnetic field isWhy are enamelled wires used to wind a solenoid?What does a soft iron core inside a solenoid do to the field?The equal and opposite forces on two parallel current-carrying wires agree withForce per unit length between parallel currents Ia and Ib a distance d apart isWires 0.1 m apart carry 10 A and 20 A in parallel. Force per metre?The ampere definition uses long parallel wires placed how far apart?Which instrument is used to measure the force between current-carrying coils in practice?One coulomb of charge crosses a conductor's section in 1 s at what current?A loop of area A carrying I has B in its plane. The torque isA 100-turn, 0.01 m^2 coil with 2 A lies in the plane of a 0.5 T field. Torque?The magnetic moment of a planar loop with N turns, current I, area A isA 50-turn coil of area 0.04 m^2 carries 0.2 A. Its magnetic moment?Seen from far away, a planar current loop is equivalent toOn the axis of a circular loop far away (x much greater than R), B varies asWhich isolated entity has never been observed, unlike electric charge?Ampere suggested that all magnetism arises fromA moving coil galvanometer gets its radial field usingIn a moving coil galvanometer, what balances the magnetic torque?The deflection of a moving coil galvanometer is proportional toA 100 ohm, 1 mA galvanometer becomes a 10 V voltmeter. Series resistance?Doubling the coil turns N in a galvanometer does what to current sensitivity?If the turns N in a galvanometer coil are doubled, voltage sensitivityRoughly how strong is the earth's magnetic field at its surface?A charged particle moves in a region with only a uniform magnetic field. What happens to its kinetic energy?In helical motion in a magnetic field, the distance moved along the field in one rotation is called theIn the definition of the ampere, each of two long parallel wires 1 m apart experiences what force per metre?A solenoid has 1000 turns per metre and carries 2 A. What is the field inside it? (mu0 = 4 pi x 10^-7)A galvanometer becomes an ammeter when we connect aA 100-turn coil of area 0.01 m^2 carries 0.5 A, with its plane parallel to a 0.4 T field. What is the torque?What is the net force on a current loop placed in a uniform magnetic field?The magnetic moment of a current loop points along the direction given by theA proton (m = 1.67 x 10^-27 kg) circles in a 1 T field. What is its frequency?If a charge's speed is doubled while it circles in the same field, its orbit radiusWires carrying 10 A and 5 A lie 0.1 m apart in parallel. What is the force per metre?A solenoid of 500 turns and length 0.5 m carries 4 A. What is the central field?The current sensitivity of a galvanometer is defined as deflection per unitWhich Danish physicist noticed a compass needle deflect near a current-carrying wire?A proton moves along +x in a field along +y. The magnetic force on it points alongIn the Biot-Savart law, the field from a current element varies with distance r roughly asThe cyclotron is a machine used toThe Lorentz force on a charge in electric and magnetic fields is given byIn a galvanometer, spring torque balances magnetic torque, so deflection is proportional toA galvanometer of 100 ohm, full scale 1 mA, is to read 1 A. Shunt needed is aboutIf the magnetic field is doubled, the time period of a charge circling in itA charge enters a uniform field at an angle that is neither 0 nor 90 degrees to it. Its path isAmpere's circuital law is to the Biot-Savart law as which law is to Coulomb's law?An alpha particle and a proton enter a field at equal speed. The ratio of their radii (alpha : proton) isThe permeability of free space has the value