(a) 1/x (b) 1/x2 (c) x (d) x2 Answer-c (7)
A rubber cord catapult has cross-sectional area 25mm2 and initial length of rubber cord is It is stretched to and then released to project a missile of mass (Taking YRUBBER=5×108N/m2) velocity of projected missile is (a) 20 m/s …
Two wires A and B are of same materials. Their lengths are in the ratio 1 : 2 and diameters are in the ratio 2 : 1 when stretched by force FA and FB respectively they get equal increase in …
The area of cross section of a steel wire (Y=2.0×1011 N/m2) is 0.1 cm2 . The force required to double its length will be (a) 2×1012 N/m …
(a) Length of the wire (b) Radius of the wire (c) Material of the wire (d) Shape of the cross section Answer-c (13)
(a) Sliding of molecular layer is much easier than compression or expansion (b) Reciprocal of bulk modulus of elasticity is called compressibility (c) It is difficult to twist a long rod as compared to small rod (d) Hollow shaft is …
(a) Length (b) Breadth (c) Shape (d) Volume Answer-c (5)
A rod of length l and radius r is joined to a rod of length l/2 and radius r/2 of same material. The free end of small rod is fixed to a rigid base and the free end of larger …
(a) 0.002 (b) 0.004 (c) 0.008 (d) 0.016 Answer-b (22)
A metal bar of length L and area of cross-section A is clamped between two rigid supports. For the material of the rod, its Young’s modulus is Y and coefficient of linear expansion is . If the temperature of the …
A copper wire of length 4.0m and area of cross-section 1.2 cm2 is stretched with a force of 4.8×103N. If Young’s modulus for copper is .2×1011 N/m2 the increase in the length of the wire will be (a) 1.33 mm …
If the interatomic spacing in a steel wire is 3.0Å and Ysteel =20×1010 N/m2 then force constant is (a) 6×10-2 N/Å (b) 6×10-9 N/Å (c) 4×10-5 N/Å (d) 6×10-5 N/Å Answer-b (19)
On applying a stress of 20×108 N/m2 the length of a perfectly elastic wire is doubled. Its Young’s modulus will be (a) 40×108 N/m2 (b) 20×108 N/m2 (c) 10×108 N/m2 (d) 5×108 N/m2 Answer-b (7)
How much force is required to produce an increase of 0.2% in the length of a brass wire of diameter 0.6 mm (Young’s modulus for brass =0.9×1011 N/m2 ) (a) Nearly 17 N …
A 5 m long aluminium wire ( Y=7×1010 N/m2) of diameter 3 mm supports a 40 kg mass. In order to have the same elongation in a copper wire ( Y=12×1010 N/m2) of the same length under the same weight, the …
Two similar wires under the same load yield elongation of 0.1 mm and 0.05 mm respectively. If the area of cross- section of the first wire is 4mm2 then the area of cross section of the second wire is (a) …
A steel wire of lm long and cross section area is 1mm2 hang from rigid end. When weight of 1kg is hung from it then change in length will be (given Y=2×1011N/m2) (a) 0.5 mm (b) 0.25 mm (c) …
A rubber pipe of density 1..5×103 N/m2 and Young’s modulus is 5×106 N/m2 suspended from the roof. The length of the pipe is 8 m. What will be the change in length due to its own weight (a) 9.6 m …
A rod is fixed between two points at 20°C. The coefficient of linear expansion of material of rod is 1.1×10-5/°C and Young’s modulus is 1.2×1011 N/m2 . Find the stress developed in the rod if temperature of rod becomes 10°C …
The coefficient of linear expansion of brass and steel are α1 and α2 . If we take a brass rod of length l1 and steel rod of length l2 at 0°C, their difference in length (l2-l1) will remain the same at …
A wire of cross-sectional area is 3mm2 first stretched between two fixed points at a temperature of 20°C. Determine the tension when the temperature falls to 10°C. Coefficient of linear expansion α=10-5 °C-1 and Y=2×1011 N/m2 (a) 20 N (b) 30 …
The relation between λ,ηand K for a elastic material is (a) (1/η)=(1/3λ)+(1/9k) (b) (1/k)=(1/3λ)+(1/9η) (c) (1/λ)=(1/3k)+(1/9η) …
The ratio of two specific heats of gas CP/CV for argon is 1.6 and for hydrogen is 1.4. Adiabatic elasticity of argon at pressure P is E. Adiabatic elasticity of hydrogen will also be equal to E at the pressure …
A force of 103 newton stretches the length of a hanging wire by 1 millimetre. The force required to stretch a wire of same material and length but having four times the diameter by 1 millimetre is (a) 4×103 N …
Two wires of the same material have lengths in the ratio 1 : 2 and their radii are in the ratio 1:√2 . If they are stretched by applying equal forces, the increase in their lengths will be in the …
A steel ring of radius r and cross-section area ‘A’ is fitted on to a wooden disc of radius R(R>r). If Young’s modulus be E, then the force with which the steel ring is expanded is (a) AE(R/r) …
The force required to stretch a steel wire of cross-section 1 cm2 to 1.1 times its length would be(Y=2×1011 N/m2) (a) 2×106 N (b) 2×103 N (c) 2×10-6 N …
In steel, the Young’s modulus and the strain at the breaking point are 2×1011 N/m2 and 0.15 respectively. The stress at the breaking point for steel is therefore (a) 1.33×1011 N/m2 (b) 1.33×1012 N/m2 (c) 7.5×10–13 N/m2 …
Young’s modulus of rubber is 104 N/m2 and area of cross-section is 2 cm2 . If force of 2×105 dynes is applied along its length, then its initial length l becomes (a) 3L …
For silver, Young’s modulus is 7.25×1010 N/m2 and Bulk modulus is 11×1010 N/m. Its Poisson’s ratio will be (a) – 1 …
The length of a wire is 1.0 m and the area of cross-section is 1.0×10-2 cm2 . If the work done for increase in length by 0.2 cm is 0.4 joule, then Young’s modulus of the material of the wire …
46.A force of 200 N is applied at one end of a wire of length 2 m and having area of cross-section 10-2 cm2 . The other end of the wire is rigidly fixed. If coefficient of linear expansion of the …
40. The interatomic distance for a metal is 3×10-10 m . If the interatomic force constant is 3.6×10–9 N/Å , then the Young’s modulus in N/m2 will be (a) 1.2×1011 …
Longitudinal stress of 1 kg/mm2 is applied on a wire. The percentage increase in length is (Y=1011 N/m2) (a) 0.002 (b) 0.001 (c) 0.003 …
33. An aluminum rod (Young’s modulus=7×109 N/m2) has a breaking strain of 0.2%. The minimum cross-sectional area of the rod in order to support a load of 104 Newton’s is (a) 1×10-2 m2 …
32. A rod of length l and area of cross-section A is heated from 0°C to 100°C. The rod is so placed that it is not allowed to increase in length, then the force developed is proportional to (a) …
31.The temperature of a wire of length 1 metre and area of cross-section is 1 cm2 is increased from 0°C to 100°C. If the rod is not allowed to increase in length, the force required will be (α=10-5/°C and Y=1011 …
30. Increase in length of a wire is 1 mm when suspended by a weight. If the same weight is suspended on a wire of double its length and double its radius, the increase in length will (a) 2 mm …
29. An area of cross-section of rubber string is 2 cm2 . Its length is doubled when stretched with a linear force of 2×105dynes. The Young’s modulus of the rubber in dyne/cm2 will be (a) 4×105 …
28. Steel and copper wires of same length are stretched by the same weight one after the other. Young’s modulus of steel and copper are 2×1011 N/m2 and 1.2×1011 N/m2 . The ratio of increase in length (a) 2/5 …