MCQ
Five identical rods are joined as shown in figure. Point $A$ and $C$ are maintained at temperature $120^o C$ and $20^o C$ respectively. The temperature of junction $B$ will be....... $^oC$
- A$100$
- B$80$
- ✓$70$
- D$0$
✓
Answer
Correct option: C.
$70$
c
(c) If thermal resistance of each rod is considered $R$ then, the given combination can be redrawn as follows
(c) If thermal resistance of each rod is considered $R$ then, the given combination can be redrawn as follows
(Heat current)$_{AC} =$ (Heat current)$_{AB}$
$\frac{{(120 - 20)}}{R} = \frac{{(120 - \theta )}}{R}$
==> $\theta = 70^\circ C$
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
A ball is dropped from a height $h$. If the coefficient of restitution be $e$, then to what height will it rise after jumping twice from the ground
→The average translational kinetic energy of a hydrogen gas molecules at $NTP$ will be
→[Boltzmann’s constant ${k_B} = 1.38 \times {10^{ - 23}}J/K]$
A thin horizontal circular disc is rotating about a vertical axis passing through its centre. An insect is at rest at a point near the rim of the d isc. The insect now moves along a diameter of the disc to reach its other end . During the journey of the insect, the angular speed of the disc.
The potential energy function for the force between two atoms in a diatomic molecule is approximately given by $U(x)=$ $\;\frac{a}{{{x^{12}}}} - \frac{b}{{{x^6}}}$ where a and b are constants and $x $ is the distance between the atoms. If the dissociation energy of the molecule is $D = [ U ( x = \infty) - U_{ at\ equilibrium}], D$ is
→A body released from the top of alls through a height of 5m during the first second of its fall and 35m during the last second of its fall. The height of the tower is:
A pulley of radius $1.5\,m$ is rotated about its axis by a force $F =\left(12 t -3 t ^{2}\right)\,N$ applied tangentially (while $t$ is measured in seconds). If moment of inertia of the pulley about its axis of rotation is $4.5\,kg\,m ^{2}$, the number of rotations made by the pulley before its direction of motion is reversed, will be $\frac{K}{\pi}$. The value of $K$ is $.....$
→An electrically maintained tuning fork vibrates with constant frequency and constant amplitude. If the temperature of the surrounding air increases but pressure remains constant, the sound produced will have:
- Larger wavelength.
- Larger frequency.
- Larger velocity.
- Larger time period.
Surface tension of a soap solution is $1.9 \times {10^{ - 2}}N/m$. Work done in blowing a bubble of $2.0\, cm$ diameter will be
→A crystal has a coefficient of expansion $13\times10^{-7}$ in one direction and $231\times10^{-7}$ in every direction at right angles to it. Then the cubical coefficient of expansion is
→The speed of a body moving with uniform acceleration is $u$. This speed is doubled while covering a distance $S$. When it covers an additional distance $S$, its speed would become
→