Practice MCQ Questions and answers on Physics-GK

The cassette tape contains a magnetic strip wound around two spools. Tiny magnetic particles are randomly scattered throughout the tape. A tape recorder should not be kept near a magnet as the latter can cause the magnetic material to be pushed and pulled out of place. Rearranging the magnetic particles erases the sound.

Eddy current is generated by Induction.

A capacitor (originally known as condenser) is a passive two-terminal electrical component used to store energy in an electric field. Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass, in filter networks, for smoothing the output of power supplies, in the resonant circuits that tune radios to particular frequencies, in electric power transmission systems for stabilizing voltage and power flow, and for many other purposes. The capacitance is greatest when there is a narrow separation between large areas of conductor; hence capacitor conductors are often called plates, referring to an early means of construction.

All Electrostatic Copiers work under the premise that a charge of electricity is placed on an Image Drum which has the ability to retain the electric charge much like a capacitor holds its charge but with the ability to hold or release the charge depending on how much light and darkness is applied to the Image Drum. A photocopier (also known as a copier or copy machine) is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat. Copiers can also use other technologies such as ink jet, but xerography is standard for office copying.

All Electrostatic Copiers work under the premise that a charge of electricity is placed on an Image Drum which has the ability to retain the electric charge much like a capacitor holds its charge but with the ability to hold or release the charge depending on how much light and darkness is applied to the Image Drum. A photocopier (also known as a copier or copy machine) is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat. Copiers can also use other technologies such as ink jet, but xerography is standard for office copying.

Argon, copper, silver are diamagnetic.

At Curie temperature, a ferromagnetic substance is converted into paramagnetic substance.

In classical electromagnetism, magneti-zation or magnetic polari-zation is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized. The magnetization of a material is done by electric current. By the process of magnetization, the formed pieces develop North polarity on one end or side and South polarity on the other end or side, in a very short period of time.

Magnetic domains normally occur in iron.

A small piece of a substance is weakly attracted by a strong magnetic field. The substance is paramagnetic.