CBSE Class 12 (Science) Electromagnetic Induction — practice questions
94 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 (Science) Electromagnetic Induction in the app →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: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:Which unit is used for magnetic flux in the SI system?Magnetic flux through a surface is best described as which kind of quantity?Which scientist's name is given to the SI unit of inductance?Inductance is a quantity of which type?Around which decade did Faraday and Henry perform their induction experiments?What did Faraday compare his new discovery to when asked what use it was?The emf produced by self-induction in a coil is also known as what?In electromagnetism, self-inductance plays a role similar to which mechanical property?An ac generator converts which form of energy into electrical energy?In an ac generator, the ends of the rotating coil reach the outside circuit through what?Who is credited with developing the ac generator, as described in NCERT Class 12 Physics?Which statement about the coil of a simple ac generator is correct?What name is given to the rotating coil of an ac generator?A 500 MW generator could light how many 100 W bulbs at once?A rod 0.5 m long moves at 4 m/s at right angles to a 0.2 T field and its own length. What emf appears across iA uniform 0.5 T field is normal to a 0.2 square metre loop. How much flux passes through it?A 200-turn coil of area 0.02 square metre spins at 100 rad/s in a 0.5 T field. What is its peak emf?The flux through a single-turn loop falls from 0.04 Wb to 0.01 Wb in 0.3 s. What is the average induced emf?The current in a nearby coil changes at 4 A/s and the mutual inductance is 0.5 H. What emf is induced?A 5 H coil has its current changing at 2 A/s. What is the magnitude of the self-induced emf?A 2 H inductor carries a steady 3 A. How much energy is stored in its magnetic field?A coil of 500 turns links a flux of 2 x 10^-4 Wb per turn when it carries 0.5 A. What is its inductance?A coil of area 0.5 square metre sits in a 0.4 T field with its normal at 60 degrees to the field. What is the When the emf of a rotating coil is at its peak value, what is true of the flux through the coil?Generators driven by high-pressure steam from burning coal are called what?A generator coil turns at 50 revolutions per second. How long does one full cycle of its emf last?The dimensions of inductance equal the dimensions of flux divided by those of which quantity?In the energy stored in a coil, to which mechanical quantity is L analogous?By Lenz's law, how does an induced current flow?For coils 1 and 2, how are the mutual inductances M12 and M21 related?Lenz's law says the induced current also exerts a mechanical force that does what?