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Which of the following is commonly used as an insulator in electrical applications?
Copper
Aluminum
Bakelite
Iron
Bakelite
Bakelite is a synthetic plastic material that acts as an electrical insulator because it lacks free charge carriers. Insulators are substances that significantly resist the flow of electric current due to their high electrical resistivity.
Bakelite is a synthetic plastic material that acts as an electrical insulator because it lacks free charge carriers. Insulators are substances that significantly resist the flow of electric current due to their high electrical resistivity.
Think of a conductor as a busy highway where cars (electrons) move freely, while an insulator like Bakelite is like a locked gate that stops all traffic from passing through.
B-I-P: Bakelite Is Polymer (Insulator).
╧Б=lRAтАЛ тАФ defines electrical resistivity where R is resistance, A is cross-sectional area, and l is length.
╧Г=╧Б1тАЛ тАФ relates electrical conductivity to resistivity.
In conductors like metals, valence electrons are loosely held and act as free charge carriers that allow current flow (I=nAevdтАЛ). In Bakelite, which is a thermosetting polymer (phenol-formaldehyde resin), all electrons are tightly bound within covalent bonds in a cross-linked structure. Because there are no free electrons to drift in an electric field, the material cannot support electrical conduction.
Bakelite is a thermosetting polymer known for its high heat resistance and electrical insulation.
Materials with low electrical conductivity (or high resistivity) are classified as insulators.
Metals like Copper, Aluminum, and Iron have low resistivity and are excellent conductors.
Excellent dielectric strength
High thermal stability (does not melt easily)
Chemical resistance
Brittle nature compared to thermoplastic polymers
Not recyclable due to its cross-linked chemical structure
Electrical switch boards and sockets
Handles for kitchen cookware
Insulated handles for tools
Standard resistivity for good insulators is typically in the range of 1010 to 1020╬йтЛЕm.
Copper, Aluminum, and Iron are metals and therefore conductors of electricity.
C is correct тАФ Bakelite is a synthetic plastic that functions as an electrical insulator, effectively blocking the flow of electric current.
In competitive exams, always identify if an element is a metal (Conductor) or a polymer/non-metal (usually Insulator) to eliminate options quickly.