Understanding Magnets and Magnetism

Front

Bar magnet: rectangular magnet with distinct north & south poles generating a magnetic field.

Back

A bar magnet is a rectangular magnet with distinct north and south poles that generates a magnetic field.

Answer explanation

A bar magnet is specifically a rectangular magnet characterized by its distinct north and south poles, which create a magnetic field. The other options incorrectly describe its function or shape.

Front

Define a permanent magnet.

Back

A permanent magnet generates a constant magnetic field.

Answer explanation

A permanent magnet is defined as a material that generates a constant magnetic field, distinguishing it from temporary magnets and electromagnets, which require external power or only attract metals temporarily.

Front

Characteristics of hard materials in magnetism?

Back

High coercivity and remanence.

Answer explanation

A hard material is characterized by high coercivity, meaning it resists demagnetization, and high remanence, which indicates it retains significant magnetization after the external field is removed.

Front

Behavior of soft materials when magnetized?

Back

A soft material becomes magnetically polarized and easily gains and loses magnetism.

Answer explanation

A soft material, when magnetized, becomes magnetically polarized, allowing it to easily gain and lose magnetism. This is in contrast to hard materials, which retain magnetism permanently.

Front

Material magnetisation occurs when magnetic domains align in the same direction, granting magnetic properties.

Back

Magnetic domains align in the same direction.

Answer explanation

A material is magnetised when its magnetic domains align in the same direction, which allows it to exhibit magnetic properties. This alignment is what gives the material its magnetism.

Front

Difference between magnetised and unmagnetised materials?

Back

Magnetised materials have a net magnetic field from aligned domains; unmagnetised do not.

Answer explanation

Magnetised materials have aligned magnetic domains, resulting in a net magnetic field. In contrast, unmagnetised materials lack this alignment and therefore do not exhibit a magnetic field.

Front

Induced magnetism:

Back

Temporary magnetization of a material due to an external magnetic field.

Answer explanation

Induced magnetism refers to the temporary magnetization of a material when exposed to an external magnetic field. This effect is not permanent and typically occurs in ferromagnetic materials, distinguishing it from permanent magnetization.

Front

Magnetic field:

Back

A region where magnetic forces can be observed.

Answer explanation

A magnetic field is defined as a region where magnetic forces can be observed, affecting magnetic materials and charged particles. This distinguishes it from the incorrect options that describe unrelated concepts.

Front

Magnetic field lines represent:

Back

Direction and strength of a magnetic field.

Answer explanation

Magnetic field lines illustrate the direction and strength of a magnetic field. They show how the field behaves in space, with denser lines indicating stronger fields and the arrows indicating the direction of the force.

Front

Purpose of a plotting compass?

Back

Determines direction and assists in navigation.

Answer explanation

A plotting compass is primarily used to determine direction and assist in navigation, making it essential for map reading and outdoor activities. The other options do not accurately describe its main function.