Question
How does electrical resistance depend on the dimensions of an electronic (metallic) conductor?
✓
Answer
The electrical resistance of an electronic conductor is linearly proportional to its length (l) and inversely proportional to its cross section area a.
Thus, $R \propto l ; R \propto \frac{1}{a}$
$
\therefore R \propto \frac{l}{a} \text { or } R =\rho \times \frac{l}{a}
$
where the proportionality constant $p$ is called specific resistance. IUPAC recommends the term resistivity for specific resistance.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
How will you bring about the following conversions?
acetone to 2-methylpropan-2-ol
acetone to 2-methylpropan-2-ol
An element A and B constitute bcc type crystalline structure. Element A occupies body centre position and B is at the corners of cube. What is the formula of the compound? What are the coordination numbers of A and B ?
On the basis of valence bond theory explain the nature of bonding in $[CoF_6]^{3-}$ ion.
Write the $\text{IUPAC}$ name of $[Co(NO₂)_3 (NH_3)_3].$
→Write the $\text{IUPAC}$ name of $[Co(NO₂)_3 (NH_3)_3].$
Explain the change in entropy for the following processes:
(i) $2 H _2 O _{2 \text { (l) }} \rightarrow 2 H _2 O _{\text {(l) }}+ O _{2 \text { (g) }}$
(ii) $2 H _{2 \text { (g) }}+ O _{2( g )} \rightarrow 2 H _2 O _{\text {(l) }}$
(iii) When ice melts at $0^{\circ} C$ and water vaporises at $100^{\circ} C$.
→(i) $2 H _2 O _{2 \text { (l) }} \rightarrow 2 H _2 O _{\text {(l) }}+ O _{2 \text { (g) }}$
(ii) $2 H _{2 \text { (g) }}+ O _{2( g )} \rightarrow 2 H _2 O _{\text {(l) }}$
(iii) When ice melts at $0^{\circ} C$ and water vaporises at $100^{\circ} C$.
How does Frenkel defect arise?
Calculate the work done in the following reaction at $50^{\circ} C$. State whether work is done on the system or by the system.
$SO _{2( g )}+\frac{1}{2} O _{2( g )} \longrightarrow SO _{3( g )}$.
→$SO _{2( g )}+\frac{1}{2} O _{2( g )} \longrightarrow SO _{3( g )}$.
The enthalpy change for the atomisation of $10^{10}$ molecules of ammonia is $1.94 \times 10^{-11} kJ$. Calculate the bond enthalpy of $N - H$ bond.
→Write reaction to convert acetic acid into methylamine.
A substance crystallizes in fcc structure. The unit cell edge length is $367.8 pm$. Calculate the molar mass of the substance if its density is $21.5 g/cm^3$.
→What is the molar mass of a solute if a solution prepared by dissolving $0.822 g$ of it in $0.3 \ dm^3$ of water has an osmotic pressure of $0.196 \ atm.$ at $298 K$?
→