Conductor Properties | MCQs

Explanation

If two metallic conductors have the same resistivity, they can be differentiated based on their temperature coefficient. 

The temperature coefficient of resistivity indicates how much the resistivity of a material changes with a temperature change.

Materials with the same resistivity can have different temperature coefficients, meaning their resistance will change differently as temperature changes. 

Explanation

Silicon is a metalloid with properties ideal for controlling electrical current.

It's the most widely used material in semiconductor devices like transistors and chips.

Explanation

When a wire is stretched to double its length, its resistance becomes:

R' = ρ × (2L) / (A/2) = 4 × R

So, the new resistance is 4r ohms

Explanation

An insulator has a completely filled valence band. 

Explanation: In an insulator, all the valence electrons are tightly bound to their atoms and cannot move freely, resulting in a filled valence band.

Since there are no electrons available in the conduction band, they cannot move to it and conduct electricity. 

Explanation

When the length of a copper wire is doubled, the resistivity remains the same.

Resistivity is an intrinsic property of the material and does not change with the dimensions of the wire.

However, the resistance will double, as resistance is directly proportional to the length of the wire.