EASY
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What is the force constant k of the spring?

Important Questions on Matter : Structure and Properties

HARD
A steel wire of length 4.5 m and cross-sectional area 3×105 m2 stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area of 4×105 m2 under a given load. The ratio of the Young’s modulus of steel to that of copper is:
MEDIUM
A stretching force of 100 kN acts on a steel rod of length 1 m and radius 10 mm. The percentage strain produced in the rod is: (YSteel=2×1011 N m-2)
MEDIUM
A cube is subjected to a uniform volume compression. If the side of the cube decreases by 1% the bulk strain is
HARD
The area of cross-section of steel wire is 0.1 cm2 and Young’s modulus of steel is  2×1011 N m2. The force required to stretch the steel wire by 0.1% of it's length is:
MEDIUM
A steel rod of length 1 m and radius 10 mm is stretched by a force 100 kN along its length. The stress produced in the rod is: (YSteel = 2×1011 N m2 )
MEDIUM
One end of a nylon rope of length 4.5 m and diameter 6 mm is fixed to a free limb. A monkey weighing 100 N jumps to catch the free end and stays there. The elongation of the rope is: (Given Young’s modulus of nylon = 4.8×1011 N m-2 )
EASY
A copper and a steel wire of same diameter are connected end to end. A deforming force F is applied to this composite wire which causes a total elongation of 1 cm. The two wires will have:
EASY
The dimensional formula of Young's modulus is MxL-1T-2. The value of x is _____.
MEDIUM
A wire stretches by an amount l under a load. If the load and radius both are increased to four times, the stretch caused in the wire is:
MEDIUM
Two wires of the same length and same material but radii in the ratio of 1:2 are stretched by unequal forces to produce equal elongation. The ratio of the two forces is
MEDIUM
A metal wire of length L1 and area of cross-section A is attached to a rigid support. Another metal wire of Length L2 and of the same cross-section area is attached to the free end of the first wire. A body of mass M is then suspended from the free end of the second wire. If Y1 and Y2 are the Young’s moduli of the wires respectively, the effective force constant of the system of two wires is
HARD
A 15 kg mass fastened to the end of the steel wire of unstretched length 1.0 m is whirled in a vertical circle with an angular velocity of 2 rev s1. The cross-section of the wire is 0.05 cm2. The elongation of the wire when the mass is at the lowest point of it's path is: (Take g=10 m s2, Ysteel=2×1011 N m2 )
EASY
A man grows into a giant such that his linear dimensions increase by a factor of 9. Assuming that his density remains same, the stress in the leg will change by a factor of:
MEDIUM
A stone of mass m is tied to one end of a wire of length L. The diameter of the wire is D and it is suspended vertically. The stone is now rotated in a horizontal plane and makes an angle θ with the vertical. If Young’s modulus of the wire is Y, then the increase in the length of the wire is
MEDIUM
A bar of length l, breadth b and depth d is supported at its ends and is loaded at the centre by a load W. If Y is the Young’s modulus of the material of the bar then, the depression δ at the centre is:
EASY
Dimension of Strain is M0LxT0. The value of x is _____.
EASY
Dimension of a unit of Strain is MxLxTx. The value of x is  _____.
EASY
The adjacent graph shows the extension l of a wire of length 1m suspended from the top of a roof at one end and with a load W connected to the other end. If the cross-sectional area of the wire is 10-6 m2 , calculate the Young's modulus of the material of the wire.


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HARD
If the ratio of diameters, lengths and Young’s moduli of steel and brass wires shown in the figure are pq and r respectively then, the corresponding ratio of increase in their lengths would be:
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