Download App

10.2 , transmission of heat — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysics10.2 , transmission of heat1 Mark
MCQ
Two identical plates of different metals are joined to form a single plate whose thickness is double the thickness of each plate. If the coefficients of conductivity of each plate are $2$ and $3$ respectively, then the conductivity of composite plate will be
  • A
    $5$
  • ✓
    $2.4$
  • C
    $1.5$
  • D
    $1.2$
✓

Answer

Correct option: B.
$2.4$
b
(b)Thermal conductivity of composite plate
${K_{eq}} = \frac{{2{K_1}{K_2}}}{{{K_1} + {K_2}}} = \frac{{2 \times 2 \times 3}}{{2 + 3}}$$ = \frac{{12}}{5}$= $2.4$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 10.2 , transmission of heat→10.2 , transmission of heat — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

A particle of mass $m$ is moving with a uniform velocity $v_1$. It is given an impulse such that its velocity becomes $v_2$. The impulse is equal to
→
An object accelerates from rest to a velocity $27.5 \,m/s$ in $10 \,sec$ then find distance covered by object in next $10\, sec$........$m$
→
Two springs of force constants $300\, N / m$ (Spring $A$) and $400$ $N / m$ (Spring $B$ ) are joined together in series. The combination is compressed by $8.75\, cm .$ The ratio of energy stored in $A$ and $B$ is $\frac{E_{A}}{E_{B}} .$ Then $\frac{E_{A}}{E_{B}}$ is equal to
→
A particle is moving with constant speed $v$ in $x y$ plane as shown in figure. The magnitude of its angular velocity about point $O$ is .........
→
The pressure of an ideal gas is written as $E = \frac{3PV}{2}$ . Here $E$ stands for
→
Position of an ant ( $\mathrm{S}$ in metres) moving in $\mathrm{Y}-\mathrm{Z}$ plane is given by $S=2 t^2 \hat{j}+5 \hat{k}$ (where $t$ is in second). The magnitude and direction of velocity of the ant at $t=1 \mathrm{~s}$ will be :
→
Velocity of sound is maximum in
→
A small disc of radius $2\, cm$ is cut from a disc of radius $6\, cm$. If the distance between their centres is $3.2\, cm$, what is the shift in the centre of mass of the disc ....... $cm$.
→
If $\mathrm{n}$ is the number density and $\mathrm{d}$ is the diameter of the molecule, then the average distance covered by a molecule between two successive collisions (i.e. mean free path) is represented by :
→
Pick the correct options.
  1. All electrons have magnetic moment.
  2. All protons have magnetic moment.
  3. All nuclei have magnetic moment.
  4. All atoms have magnetic moment.
→