Physics · Thermal Properties of Matter

JEE Main 2024 — 4 April, Shift 1 — Question 36

The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are 8Ω8 \Omega and 10Ω10 \Omega respectively. After inserting in a hot bath of temperature 400∘C400^{\circ} \mathrm{C}, the resistance of platinum wire is :

  1. Option A:

    2Ω2 \Omega

  2. Option B:

    16Ω16 \Omega

    Correct
  3. Option C:

    8Ω8 \Omega

  4. Option D:

    10Ω10 \Omega

Answer: B

Step-by-step solution

Given R0=8Ω,R100=10Ω\mathrm{R}_{0}=8 \Omega, \mathrm{R}_{100}=10 \Omega

∴R100=R0(1+αΔT)\therefore \mathrm{R}_{100}=\mathrm{R}_{0}(1+\alpha \Delta \mathrm{T})

 Also, R400=R0(1+αΔT1)\text { Also, } \mathrm{R}_{400}=\mathrm{R}_{0}\left(1+\alpha \Delta \mathrm{T}^{1}\right)

∴10=8(1+α×100)⇒100α=14\therefore 10=8(1+\alpha \times 100) \Rightarrow 100 \alpha=\frac{1}{4}

∴R400=8(1+400α)=8(1+1)=16Ω\therefore \mathrm{R}_{400}=8(1+400 \alpha)=8(1+1)=16 \Omega

Answer key and solution verified before publishing.

Practise Thermal Properties of Matter

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Exam
JEE Main 2024
Subject
Physics
Chapter
Thermal Properties of Matter
Topic
Thermal Expansion of Solids and its Applications
The resistances of the platinum wire of a platinum resistance… | JEE Main 2024 PYQ with Solution · DhiX AI