CBSE Class 12 Electromagnetic Induction — practice questions
68 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 Electromagnetic Induction in the app →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:The SI unit of magnetic flux is the:The SI unit of inductance is the:Induced emf depends on the time rate of change of:The emf Blv produced by a moving conductor is called:Whose experiments led to modern generators and transformers?Lenz's law fixes which feature of the induced emf?Moving a magnet towards a coil induces in the coil an:The induced current opposes the change that produced it, because:Because the induced current opposes the motion, the mover must:The constant linking flux linkage to current is called:Inductance depends only on the coil's geometry and its:The constant M linking two neighbouring coils is called:The constant L for a single coil is called its:Mutual inductance is also called the coefficient of:An alternative name for the SI unit of magnetic flux is:Joseph Henry is credited in the text with discovering:If the induced current did not oppose the change, one could get:A galvanometer connected to a coil shows deflection only when:Flux through a coil can be changed without moving it, by changing:The negative sign in Faraday's law expresses which law?Faraday's law needs the notion of a quantity called magnetic:Magnetic flux is defined in the same way as flux that is:The induced emf equals the rate of change of flux with respect to:A steady, unchanging magnetic flux through a circuit induces an emf of:The negative sign in Faraday's law indicates the induced current's:For a closely wound coil, the flux change through each turn is:Doubling the number of turns of a coil changes the induced emf by:An emf produced by moving a conductor in a field is called:Motional emf shows an emf can be made without varying the:Motional emf can also be explained by invoking the force named after:An induced emf in a loop can be produced only by changing the:A galvanometer shows no deflection when the magnet is held:A current may be induced in a coil by flux change from another coil that is:The flux through a coil is proportional to its:Induction between two neighbouring coils is called inductance that is:Mutual inductance is also called the coefficient of mutual:Mutual inductance is worked out for two solenoids that are:An emf induced in a single isolated coil by its own flux change is:The constant in self-induction is the coefficient of self:Flux linkage through a coil of N turns is proportional to the:The proportionality of flux to current holds if the coil geometry is:Both mutual and self induction arise from a change in: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: