JEE Main Electromagnetic Induction — practice questions
54 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice JEE Main Electromagnetic Induction in the app →Faraday's law of electromagnetic induction states EMF induced equals:Lenz's law states the induced current direction is such that it:SI unit of magnetic flux is:Mutual inductance M between two coils is defined by EMF induced in coil 2:Self-inductance L of a coil relates EMF to:Energy stored in an inductor of inductance L carrying current I:Magnetic flux Φ = B A cos θ. If a coil of area 0.1 m² in B = 0.5 T is rotated from θ=0° to θ=60° in 0.2 s, aveA rod of length L moves with velocity v perpendicular to magnetic field B. Motional EMF:In a transformer with N₁ = 100 (primary), N₂ = 500 (secondary), if input is 10 V, output is:In LR circuit, time constant τ:For an ideal inductor in AC circuit at angular frequency ω, inductive reactance:For an ideal capacitor in AC, capacitive reactance:In an LCR series AC circuit, impedance:Resonance in series LCR circuit occurs when:RMS value of an AC voltage with peak V₀:Average power in AC LCR circuit:A 100-turn coil of area 200 cm² is rotated at 50 rev/s in a field of 0.05 T. Peak EMF:A solenoid has L = 2 H. Current decreases from 5 A to 1 A in 0.1 s. EMF induced:In a step-down transformer with 1000:100 turn ratio (primary:secondary), 220 V input, 1 A secondary current. PQuality factor Q for series LCR at resonance:Two coils with self-inductances L₁ = 4 H, L₂ = 9 H. Maximum possible mutual inductance:Energy density of magnetic field B in vacuum:In an LR circuit with V = 12 V, R = 4 Ω, L = 2 H, current after t = 0.5 s:A capacitor C in series with inductor L (LC circuit) oscillates with frequency:In AC circuit with only inductor, average power consumed over one full cycle:For an AC generator with EMF ε(t) = ε₀ sin(ωt), the RMS EMF:Phase difference between voltage and current in pure capacitor in AC:Inductive reactance increases linearly with frequency. At f = 50 Hz, X_L = 100 Ω. At f = 200 Hz, X_L =A bar magnet pushed into a coil at rest causes the galvanometer needle to kick because:A copper rod of length $0.5$ m slides at $4$ m/s perpendicular to a $0.2$ T field. The motional EMF is:A coil of self inductance $0.2$ H carries $5$ A. The magnetic energy stored is:A bar magnet falling into a vertical copper tube on the lab bench drops more slowly than in free fall because:You push a bar magnet's north pole into a coil wired to a galvanometer. The needle:You now hold the magnet still inside the coil. The galvanometer shows:You pull the magnet away instead of pushing it in. The deflection:You move the same magnet faster. The deflection becomes:Two coils sit still. You press the tapping key in the battery coil. The other coil's galvanometer shows:You keep the key pressed for a whole minute. During that minute the galvanometer shows:You slide an iron rod into the two coils along their axis. The deflection:A meter reads the magnetic flux through a coil. Its reading is in:Faraday's law says the induced emf equals the time rate of change of:To get a bigger induced emf from the same flux change, you should:A closed loop sits still between two very strong fixed magnets. Is a current induced?Lenz's law says the induced current always opposes the:You push a magnet towards a coil. By Lenz's law the coil pushes the magnet:If the induced current helped the magnet instead, a gentle push would give endless speed. This breaks:Where does the work you do pushing the magnet into the coil end up?A loop moves while lying fully inside a uniform magnetic field. The induced current is:A copper plate swings between the poles of a magnet and soon stops. The cause is:Cutting slots in the swinging copper plate makes it:Some trains brake with electromagnets held above the rails. The braking feels:A magnet dropped through an aluminium pipe, compared with a PVC pipe, takes:A coil is labelled 2 H. The H stands for the unit called the:The coil of an AC generator connects to the outside circuit through: