EASY
Earn 100

A bimetallic strip of lead and nickel has a total thickness of 8cm (4cm each). The strip is straight at a temperature of 300K. The coefficient of linear expansion of lead is 29×10-6 K-1 and that of nickel is 16×10-6 K-1. If the strip is heated to 400K, then the radius of curvature of the strip is close to

50% studentsanswered this correctly

Important Questions on Thermal Properties of Matter

MEDIUM
A uniform cylindrical rod of length L and radius r, is made from a material whose Young’s modulus of Elasticity equals Y. When this rod is heated by temperature T and simultaneously subjected to a net longutudinal compressional force F, its length remains unchanged. The coefficient of volume expansion, of the material of the rod, is (nearly) equal to:
EASY
The value of coefficient of volume expansion of glycerin is 5×10-K-1. The magnitude of fractional change in the density of glycerin for a rise of 40 oC in its temperature is:
EASY
A horizontal steel railroad track has a length of 100 m when the temperature is 25°C. The track is constrained from expanding or bending. The stress on the track on a hot summer day, when the temperature is 40°C, is (Note: The linear coefficient of thermal expansion for steel is 1.1×10-5/C and the Young's modulus of steel is 2×1011 Pa
MEDIUM

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : When a rod lying freely is heated, no thermal stress is developed in it.

Reason R : On heating, the length of the rod increases.

In the light of the above statements, choose the correct answer from the options given below:

MEDIUM
A compressive force, F is applied at the two ends of a long thin steel rod. It is heated, simultaneously, such that its temperature increases by ΔT. The net change in its length is zero. Let l be the length of the rod, A its area of cross-section, Y its Young's modulus, and α its coefficient of linear expansion. Then, F is equal to:
MEDIUM
The pressure that has to be applied to the ends of a steel wire of length 10 cm to keep its length constant when its temperature is raised by 100 °C is :
(For steel, Young's modulus is 2×1011 N m-2 and coefficient of thermal expansion is 1.1×10-5 K-1)
MEDIUM
A simple pendulum made of a bob of mass m and a metallic wire of a negligible mass has a time period of 2 s at T=0°C. If the temperature of the wire is increased, and the corresponding change in its time period is plotted against its temperature, the resulting graph is a line of slope S. If the coefficient of linear expansion of metal is α, then the value of S is
MEDIUM
A rod, of length L at room temperature and uniform area of cross section A, is made of a metal having coefficient of linear expansion α /°C It is observed that an external compressive force F is applied on each of its ends, prevents any change in the length of the rod when its temperature rises by T K Young's modulus, Y for this metal is:
EASY
Coefficient of linear expansion of brass and steel rods are α1 and α2. Lengths of brass and steel rods are l1 and l2, respectively. If l2-l1 is maintained the same at all temperatures, which one of the following relations holds good?
MEDIUM
Consider two thermometers, T1 and T2 of equal length which can be used to measure temperature over the range θ1 to θ2. T1, contains mercury as a thermometric liquid while T2 contains bromine. The volumes of the two liquids are the same at the temperature, θ1. The volumetric coefficients of expansion of mercury and bromine are 18×10-5 K-1 and 108×10-5 K-1, respectively. The increase in the length of each liquid is the same for the same increase in temperature. If the diameters of the capillary tubes of the two thermometers are d1 and d2 respectively, then the ratio d1:d2 would be closest to:
EASY
Two rods of different materials having coefficients of linear expansion α1, α2 and Young's modulii Y1 and Y2 respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If α1:α2=2:3, the thermal stresses developed in the two rods are equally provided Y1:Y2 is equal to
MEDIUM
A metal rod of length L and cross-sectional area A is heated through T °C. What is the force required to prevent the expansion of the rod lengthwise?
[Y = Young's modulus of the material of rod, α= coefficient of linear expansion]
HARD
A pendulum clock loses 12 s a day if the temperature is 40o C and gains 4s a day if the temperature is 20o C. The temperature at which the clock will show correct time, and the co-efficient of linear expansion α of the metal of the pendulum shaft are respectively:
EASY
A copper rod of 88 cm and an aluminum rod of unknown length have their increase in length independent of increase in temperature. The length of aluminum rod is αCu=1.7×10-5 K-1andαAl=2.2×10-5K-1 
MEDIUM
A non-isotropic solid metal cube has coefficients of linear expansion as: 5× 10 5 / o C along the x-axis and 5× 10 6 / o C along the y and the z-axis. If the coefficient of volume expansion of the solid is C× 10 6 / o C , then the value of C is _____________
HARD
The ends Q and R of two thin wires, PQ and RS, are soldered (joined) together. Initially each of the wires has a length of 1 m at 10°C. Now the end P is maintained at 10°C, while the end S is heated and maintained at 400°C. The system is thermally insulated from its surroundings. If the thermal conductivity of wire PQ is twice that of the wire RS and the coefficient of linear thermal expansion of PQ is 1.2×10-5 K-1, the change in length of the wire PQ is
HARD
A metal rod of cross-sectional area 10-4 m2 is hanging in a chamber kept at 20°C with a weight attached to its free end. The coefficient of thermal expansion of the rod is 2.5×10-6 K-1 and its Young's modulus is 4×1012 N m-2. When the temperature of the chamber is lowered to T, then a weight of 5000 N needs to be attached to the rod, so that its length is unchanged. Then, T is
HARD
At 40°C, a brass wire of 1 mm radius is hung from the ceiling. A small mass, M is hung from the free end of the wire. When the wire is cooled down from 40°C  to 20°C it regains its original length of 0.2 m. The value of M is close to:
(Coefficient of linear expansion and Young’s modulus of brass are 10-5/°C and 1011 N/m2, respectively; g=10 m s-2 )