Hooke's Law and Modulus of Elasticity

IMPORTANT

Hooke's Law and Modulus of Elasticity: Overview

This topic covers concepts, such as, Hooke's Law, Young's Modulus of Elasticity 'Y', Increment of Length Due to Own Weight & Relation Among Coefficients of Elasticity etc.

Important Questions on Hooke's Law and Modulus of Elasticity

MEDIUM
IMPORTANT

A student performs an experiment to determine the Young’s modulus of a wire, exactly 2 m long, by Searle’s method. In a particular reading, the student measures the extension in the length of the wire to be 0.8 mm with an uncertainty of ±0.05 mm at a load of exactly 1.0 kg. The student also measures the diameter of the wire to be 0.4 mm with an uncertainty of ± 0.01 mm. Take g=9.8 m s2 (exact). The Young’s modulus obtained from the reading is

EASY
IMPORTANT

If the Young's modulus of the material of a wire is numerically equal to ten times the stress applied to a wire of length l, then the change in the length of the wire is

EASY
IMPORTANT

The bulk modulus of a liquid is 3×1010Nm-2. The pressure required to reduce the volume of liquid by 2% is :

EASY
IMPORTANT

A steel wire of cross-sectional area 3×10-6 m2 can withstand a maximum strain of 10-3. Young's modulus of steel is 2×1011 N m-2. The maximum mass this wire can hold is,

EASY
IMPORTANT

The backlash error can be eliminated in Searle's experiment, by rotating screw in

EASY
IMPORTANT

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:

MEDIUM
IMPORTANT

A Copper wire of length LCu, Young's modulus YCu, and diameter d is hung from the ceiling. An Aluminium wire of length LAl, Young's modulus YAl, and of same diameter d is joined end-to-end at the free end of the Copper wire. If under the action of a load applied at the free end of the Aluminium wire the net elongation is L, the applied load 

MEDIUM
IMPORTANT

The dimensional formula for young's modulus is

EASY
IMPORTANT

One end of a wire of 8 mm radius and 100 cm length is fixed and the other end is twisted through an angle of 45°, The angle of shear is

EASY
IMPORTANT

The ratio of shearing stress to the corresponding shearing strain is called the modulus of _____.

EASY
IMPORTANT

The dimensional formula of modulus of rigidity is ML-1T-2.

EASY
IMPORTANT

State the units and dimensions of modulus of rigidity. 

EASY
IMPORTANT

The dimensional formula of modulus of rigidity is

MEDIUM
IMPORTANT

A rubber ball is taken to a 100 m deep lake and its volume changes by 0.1%. The bulk modulus of rubber is nearly

MEDIUM
IMPORTANT

A steel rail of length 5 m and area of cross-section 40 cm2 is prevented from expanding along its length while the temperature rises by 10 °C . If coefficient of linear expansion and Young's modulus of steel are 1.2×10-5 K-1 and 2×1011 N m-2 respectively, the force developed in the rail is approximately:

MEDIUM
IMPORTANT

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 100oC is :
(For steel Young's modulus is 2 x 1011 N m-2 and coefficient of thermal expansion is 1.1 x 10-5 K-1)

EASY
IMPORTANT

The pressure of a medium is changed from 1.01×105Pa to 1.165×105Pa and change in volume is 10% keeping temperature constant. The bulk modulus of the medium is

MEDIUM
IMPORTANT

A material has Poisson’s ratio 0.2. If a uniform rod made out of it suffers longitudinal strain 4.0×103, then calculate the percentage change in its volume.

HARD
IMPORTANT

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 its path is: (Take g=10 m s2, Ysteel=2×1011 N m2 )

MEDIUM
IMPORTANT

A wire of natural length l, Young's modulus Y and area of cross-section A is extended by x. Then the energy stored in the wire is given by