01. Thermal Expansion (Linear, Area and Volume Expansion)
Thermal Properties of Matter

146504 Heat flows through two rods having same temperature difference at the ends. One rod is of length l1, radius r1 and thermal conductivity K1 and the other rod of l2,r2 and K2. The heat flow rate through the two rods will be equal, if

1 K1l2=K2l1
2 K1r12=K2l22
3 K1l2r1=K2l1r2
4 K1l2r12=K2l1r22
Thermal Properties of Matter

146506 A wire 3 m in length and 1 mm in diameter at 30C is kept in a low temperature at 170C and is stretched by hanging a weight of 10 kg at one end. The change in length of the wire is : [Y=2×1011 N/m2, g=10 m/s2 and α=1.2×10 5/C]

1 5.2 mm
2 2.5 mm
3 52 mm
4 25 mm
Thermal Properties of Matter

146507 An iron bar of length 10 m is heated from 0C to 100C. If the coefficient of linear thermal expansion of iron is 10×106/C, the increase in the length of bar is :

1 0.5 cm
2 1.0 cm
3 1.5 cm
4 2.0 cm
Thermal Properties of Matter

146508 Two rods of different materials having coefficients of thermal expansions α1 and α2 and Young's modulus Y1 and Y2 respectively are fixed between two rigid walls. The rod are heated, such that they undergo the same increase in temperature. There is no bending of rods. If α1/α2=2/3 and stresses developed in the two rods are equal, then Y1Y2 is :

1 3/2
2 1
3 2/3
4 1/2
Thermal Properties of Matter

146504 Heat flows through two rods having same temperature difference at the ends. One rod is of length l1, radius r1 and thermal conductivity K1 and the other rod of l2,r2 and K2. The heat flow rate through the two rods will be equal, if

1 K1l2=K2l1
2 K1r12=K2l22
3 K1l2r1=K2l1r2
4 K1l2r12=K2l1r22
Thermal Properties of Matter

146506 A wire 3 m in length and 1 mm in diameter at 30C is kept in a low temperature at 170C and is stretched by hanging a weight of 10 kg at one end. The change in length of the wire is : [Y=2×1011 N/m2, g=10 m/s2 and α=1.2×10 5/C]

1 5.2 mm
2 2.5 mm
3 52 mm
4 25 mm
Thermal Properties of Matter

146507 An iron bar of length 10 m is heated from 0C to 100C. If the coefficient of linear thermal expansion of iron is 10×106/C, the increase in the length of bar is :

1 0.5 cm
2 1.0 cm
3 1.5 cm
4 2.0 cm
Thermal Properties of Matter

146508 Two rods of different materials having coefficients of thermal expansions α1 and α2 and Young's modulus Y1 and Y2 respectively are fixed between two rigid walls. The rod are heated, such that they undergo the same increase in temperature. There is no bending of rods. If α1/α2=2/3 and stresses developed in the two rods are equal, then Y1Y2 is :

1 3/2
2 1
3 2/3
4 1/2
Thermal Properties of Matter

146504 Heat flows through two rods having same temperature difference at the ends. One rod is of length l1, radius r1 and thermal conductivity K1 and the other rod of l2,r2 and K2. The heat flow rate through the two rods will be equal, if

1 K1l2=K2l1
2 K1r12=K2l22
3 K1l2r1=K2l1r2
4 K1l2r12=K2l1r22
Thermal Properties of Matter

146506 A wire 3 m in length and 1 mm in diameter at 30C is kept in a low temperature at 170C and is stretched by hanging a weight of 10 kg at one end. The change in length of the wire is : [Y=2×1011 N/m2, g=10 m/s2 and α=1.2×10 5/C]

1 5.2 mm
2 2.5 mm
3 52 mm
4 25 mm
Thermal Properties of Matter

146507 An iron bar of length 10 m is heated from 0C to 100C. If the coefficient of linear thermal expansion of iron is 10×106/C, the increase in the length of bar is :

1 0.5 cm
2 1.0 cm
3 1.5 cm
4 2.0 cm
Thermal Properties of Matter

146508 Two rods of different materials having coefficients of thermal expansions α1 and α2 and Young's modulus Y1 and Y2 respectively are fixed between two rigid walls. The rod are heated, such that they undergo the same increase in temperature. There is no bending of rods. If α1/α2=2/3 and stresses developed in the two rods are equal, then Y1Y2 is :

1 3/2
2 1
3 2/3
4 1/2
Thermal Properties of Matter

146504 Heat flows through two rods having same temperature difference at the ends. One rod is of length l1, radius r1 and thermal conductivity K1 and the other rod of l2,r2 and K2. The heat flow rate through the two rods will be equal, if

1 K1l2=K2l1
2 K1r12=K2l22
3 K1l2r1=K2l1r2
4 K1l2r12=K2l1r22
Thermal Properties of Matter

146506 A wire 3 m in length and 1 mm in diameter at 30C is kept in a low temperature at 170C and is stretched by hanging a weight of 10 kg at one end. The change in length of the wire is : [Y=2×1011 N/m2, g=10 m/s2 and α=1.2×10 5/C]

1 5.2 mm
2 2.5 mm
3 52 mm
4 25 mm
Thermal Properties of Matter

146507 An iron bar of length 10 m is heated from 0C to 100C. If the coefficient of linear thermal expansion of iron is 10×106/C, the increase in the length of bar is :

1 0.5 cm
2 1.0 cm
3 1.5 cm
4 2.0 cm
Thermal Properties of Matter

146508 Two rods of different materials having coefficients of thermal expansions α1 and α2 and Young's modulus Y1 and Y2 respectively are fixed between two rigid walls. The rod are heated, such that they undergo the same increase in temperature. There is no bending of rods. If α1/α2=2/3 and stresses developed in the two rods are equal, then Y1Y2 is :

1 3/2
2 1
3 2/3
4 1/2