NCERT MCQ Solutions for Class 10 Science Chapter 12 Magnetic Effects of Electric Current

Inside a solenoid the magnetic field lines are parallel and equally spaced indicating a uniform magnetic field. This uniformity is important in many applications like MRI machines and electromagnets.

According to the right-hand thumb rule if you hold a current-carrying conductor with the thumb in the direction of current the curled fingers show the direction of magnetic field.

Magnetic field lines originate from the north pole and terminate at the south pole forming continuous closed loops without intersecting each other which maintains field direction.

Wrapping a coil around a soft iron core and passing current through the coil generates a strong temporary magnetic field enhancing the magnetism of the iron.

When electric current flows through a conductor it generates a magnetic field around it which is the basic principle behind electromagnetism and electric motors.

The magnetic field forms concentric circular lines centered on the conductor’s axis as shown by iron filings or compass needles placed around the conductor.

The strength of the magnetic field inside a solenoid is directly proportional to the amount of current flowing through the coil and the number of turns per unit length.

Fleming’s left-hand rule helps determine the direction of force experienced by a current-carrying conductor placed in a magnetic field with thumb finger and middle finger at right angles.

Electric motors convert electrical energy into mechanical energy using magnetic force between a magnetic field and current-carrying coil resulting in rotational motion.

Magnetic field lines are most concentrated near the poles of a magnet where the field is strongest as shown by closer spacing of field lines.

Magnetic field lines never intersect because at any point a field can have only one direction. Crossing lines would imply two directions at one point which is impossible.

A current-carrying solenoid exhibits magnetic properties like a bar magnet including having north and south poles and a similar magnetic field pattern along its axis.

The strength of the magnetic field around a conductor depends directly on the amount of current flowing through it not on voltage or resistance.

Soft iron is magnetically soft meaning it gains and loses magnetism easily. This makes it ideal for electromagnets which require fast switching of magnetic fields.

The magnetic field lines produced by a current-carrying circular loop are strong and concentrated at the center of the loop forming a uniform field.

According to the Biot–Savart law magnetic field around a straight conductor is inversely proportional to the distance from the wire.

Fleming’s right-hand rule helps determine the direction of induced current in a conductor moving through a magnetic field using the orientation of thumb forefinger and middle finger.

A galvanometer is a sensitive instrument used to detect the presence and direction of small electric currents in circuits especially during experiments.

In commercial use electric energy is measured in kilowatt hours which represents the energy consumed when one kilowatt of power is used for one hour.

Magnetic field lines around a bar magnet emerge from the north pole and enter the south pole forming closed continuous curves that extend outside and return inside the magnet.