Physics-
General
Easy
Question
A Copper plate is soldered between two steel plates . All the plates have the same cross- section (A) and length l. The coefficient of thermal expansions are 
and their young’s moduli are 
respectively. What force will arise in the plates if the temperature is increased by 
? (Assume that the plates suffer the same net expansion)
The correct answer is:
Thermal expansion of 
Elastic contraction of 
Net expansion of 
Either steel plate is subjected to the tensile force 
from the sides of the cu plate .Net expansion of steel = 
The plus sign is on account of the fact that there is elastic expansion, of steel plates. Since the plates suffer same net expansion 
solving we get 
Related Questions to study
physics-
Heat is extracted from a 1 kg substance at a constant rate of 2 kJ/ hour. Temperature vs-Time graph is plotted. The latent heat of substance is
Heat is extracted from a 1 kg substance at a constant rate of 2 kJ/ hour. Temperature vs-Time graph is plotted. The latent heat of substance is
physics-General
physics-
A block of steel heated to 
is left in a room to cool. Which of the curves shown in figure represents the correct cooling behaviour?
A block of steel heated to is left in a room to cool. Which of the curves shown in figure represents the correct cooling behaviour?
physics-General
physics-
The energy distribution 
with the wavelength 
for the black body radiation at temperature 
is shown in the figure. As the temperature is increased the maxima will
The energy distribution with the wavelength for the black body radiation at temperature is shown in the figure. As the temperature is increased the maxima will
physics-General
physics-
Shown below are the black body radiation curves at temperatures T1 and T2 (T2>T1) . Which of the following plots is correct
Shown below are the black body radiation curves at temperatures T1 and T2 (T2>T1) . Which of the following plots is correct
physics-General
physics-
A body cools in a surrounding which is at a constant temperature of 
. Assume that it obeys Newton's law of cooling. Its temperature 
is plotted against time t. Tangents are drawn to the curve at the points 
and 
. These tangents meet the time axis at angles of 
and 
, as shown
A body cools in a surrounding which is at a constant temperature of . Assume that it obeys Newton's law of cooling. Its temperature is plotted against time t. Tangents are drawn to the curve at the points and . These tangents meet the time axis at angles of and , as shown
physics-General
physics-
Variation of radiant energy emitted by sun, filament of tungsten lamp and welding arc as a function of its wavelength is shown in figure. Which of the following option is the correct match
Variation of radiant energy emitted by sun, filament of tungsten lamp and welding arc as a function of its wavelength is shown in figure. Which of the following option is the correct match
physics-General
physics-
The adjoining diagram shows the spectral energy density distribution 
of a black body at two different temperatures. If the areas under the curves are in the ratio 16 : 1, the value of temperature T is
The adjoining diagram shows the spectral energy density distribution of a black body at two different temperatures. If the areas under the curves are in the ratio 16 : 1, the value of temperature T is
physics-General
physics-
The plots of intensity versus wavelength for three black bodies at temperatures T1, T2 and T3 respectively are as shown. Their temperature are such that
The plots of intensity versus wavelength for three black bodies at temperatures T1, T2 and T3 respectively are as shown. Their temperature are such that
physics-General
physics-
The graph. Shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity (e) and absorptivity (a) of the two bodies
The graph. Shown in the adjacent diagram, represents the variation of temperature (T) of two bodies, x and y having same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity (e) and absorptivity (a) of the two bodies
physics-General
physics-
The figure shows a system of two concentric spheres of radii r1 and r2 and kept at temperatures T1 and T2, respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional to
The figure shows a system of two concentric spheres of radii r1 and r2 and kept at temperatures T1 and T2, respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional to
physics-General
physics-
The temperature of the two outer surfaces of a composite slab, consisting of two materials having coefficients of thermal conductivity K and 2K and thickness x and 4x, respectively are T2 and T1 (T2 > T(a) . The rate of heat transfer through the slab, in a steady state is 
, with ¦ which equal to
The temperature of the two outer surfaces of a composite slab, consisting of two materials having coefficients of thermal conductivity K and 2K and thickness x and 4x, respectively are T2 and T1 (T2 > T(a) . The rate of heat transfer through the slab, in a steady state is , with ¦ which equal to
physics-General
physics-
One end of a copper rod of uniform cross-section and of length 3.1 m is kept in contact with ice and the other end with water at 100°C. At what point along it's length should a temperature of 200°C be maintained so that in steady state, the mass of ice melting be equal to that of the steam produced in the same interval of time. Assume that the whole system is insulated from the surroundings. Latent heat of fusion of ice and vaporisation of water are 80 cal/gm and 540 cal/gm respectively
One end of a copper rod of uniform cross-section and of length 3.1 m is kept in contact with ice and the other end with water at 100°C. At what point along it's length should a temperature of 200°C be maintained so that in steady state, the mass of ice melting be equal to that of the steam produced in the same interval of time. Assume that the whole system is insulated from the surroundings. Latent heat of fusion of ice and vaporisation of water are 80 cal/gm and 540 cal/gm respectively
physics-General
physics-
Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities K1, K2, K3, K4 and K5. When points A and B are maintained at different temperatures, no heat flows through the central rod if
Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities K1, K2, K3, K4 and K5. When points A and B are maintained at different temperatures, no heat flows through the central rod if
physics-General
physics-
One end of a copper rod of length 
and area of cross-section 
is immersed in boiling water and the other end in ice. If the coefficient of thermal conductivity of copper is 92 cal/m-s-oC and the latent heat of ice is 
, then the amount of ice which will melt in one minute is
One end of a copper rod of length and area of cross-section is immersed in boiling water and the other end in ice. If the coefficient of thermal conductivity of copper is 92 cal/m-s-oC and the latent heat of ice is , then the amount of ice which will melt in one minute is
physics-General
physics-
Three rods of same dimensions are arranged as shown in figure they have thermal conductivities 
and
The points P and Q are maintained at different temperatures for the heat to flow at the same rate along PRQ and PQ then which of the following option is correct
Three rods of same dimensions are arranged as shown in figure they have thermal conductivities and The points P and Q are maintained at different temperatures for the heat to flow at the same rate along PRQ and PQ then which of the following option is correct
physics-General
