# Young's Modulus of Elasticity

## Trending Questions

**Q.**meter stick is held vertically with one end on the floor and is allowed to fall . the speed of other end when it hits floor assuming that end at floor does not slip, g=9.8ms-2

**Q.**Two wires of equal length and cross-section are suspended as shown. Their Young’s modulii are y1 and y2 respectively. The equivalent Young’s modulus will be

**Q.**a freely falling body travelled x m in n^{th } second dis†an ce travelled in (n-1)^{th} second is a)x b)x+g c)x-g d)2x+3

**Q.**

Two wires A and B of same length and of the same material have the respective radii r1 and r2. Their one end is fixed with a rigid support, and at the other ends equal twisting couple is applied. Then the ratio of the angle of twist at the end of A and The angle of twist at the end of B will be

**Q.**The internal restoring force acting per unit area of cross section is called

- Pressure
- Stress
- Strain
- Option (a) and (b) both

**Q.**

When a force is applied on a wire of uniform cross-sectional area 3×10−6m2and length 4m, the increase in length is 1mm. Energy stored in it will be

(Y=2×1011Nm−2)

0.177

*J*0.075

*J*0.150

*J*6250

*J*

**Q.**If S is stress and Y is Young’s modulus of material of a wire, the energy stored in the wire per unit volume is

- S2y
- 2yS2
- S22y
- 2S2Y

**Q.**

A 5 *metre* long wire is fixed to the ceiling. A weight of 10 *kg* is hung at the lower end and is 1 *metre* above the floor. The wire was elongated by 1 *mm*. The energy stored in the wire due to stretching is

Zero

0.05

*joule*100

*joule*500

*joule*

**Q.**

Calculate the work done, if a wire is loaded by 'Mg' weight and the increase in length is 'l'

Mgl

Zero

- Mgl2
2Mgl

**Q.**Two wires are in unison . If tension in one of the wire is increased by 2percent , 5 beats are produced per second . find the initial frequency of eac

**Q.**61. 2 bodies of masses m and Maine are allowed to fall from the same height. If air resistance be same for each body , will the 2 bodies reach the earth simultaneously? Justify

**Q.**

A body of mass M is attached to the lower end of a metal wire, whose upper end is fixed. The elongation of this wire is l.

None of these

Loss in gravitational potential energy of M is Mgl

The elastic potential energy stored in the wire is Mgl.

The elastic potential energy stored in the wire is Mgl.

**Q.**

The Youngs modulus of a wire is Y. If the energy per unit volume is E, then the strain will be

*EY*

**Q.**Read the following two statements below carefully and state, with reasons, if it is true or false. (a) The Young’s modulus of rubber is greater than that of steel; (b) The stretching of a coil is determined by its shear modulus.

**Q.**

Breaking stress is ______ for a material, but breaking force ____ and depends on _____________.

**Q.**

A uniform spring whose unstretched length is l, has a force constant K. The spring is cut into two pieces of unstretched length l1 and l2 , where l2l1=n, n being an integer. Now a mass m is made to oscillate with first spring. The time period of its oscillation would be

**Q.**

A wire 4 m long and 0.3 mm diameter is stretched by a force of 100N. If the extension in the wire is 0.3 mm, calculate the potential energy stored in the wire.

15J

25 J

15x10

^{-3}J25x10

^{-3}J

**Q.**What is the graph of free fall

**Q.**A uniform rod AB of mass m and length 2a is falling freely without rotation under gravity with AB horizontal. Suddenly the end A is fixed when speed of the rod is v. The angular speed with which the rod begins to rotate is

**Q.**

On stretching a wire of Youngs modulus Y having original length L by an amount l using a force F, the elastic energy stored per unit volume is

**Q.**The wire of a sonometer has a length of 1m and mass 5x10^{-4 }kg .It has a tension of 20N .If the wire is pulled at a point 25cm away from one end and released, the frequency of its vibrations will be how much

**Q.**A steel wire of diameter d, area of cross-section A and length 2L is clamped firmly at two points A and B which are 2L metre apart and in the same plane. A body of mass m is hung from the middle point of wire such that the middle point sags by x lower from original position. If Young’s modulus is Y then m is given by

**Q.**A mild steel wire of length 1.0 m and cross-sectional area 0.50 × 10¯² cm² is stretched, well within its elastic limit, horizontally between two pillars. A mass of 100 g is suspended from the mid-point of the wire. Calculate the depression at the midpoint.

**Q.**a balloon of gross weight W is falling vertically downward with a cons†an t accelaration a(

**Q.**

Calculate the work done, if a wire is loaded by '*Mg*' weight and the increase in length is '*l*'

Zero

*Mgl*/22

*Mgl**Mgl*

**Q.**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

- 4× 103 N
- 16×103 N
- 14×103N
- 116×103N

**Q.**A light rod with uniform cross-section of 10−4m2 is shown in the adjoining figure. The rod consists of three different materials whose lengths are 0.1 m, 0.2 m and 0.15 m respectively and whose Young's modulii are 2.5×1010Nm2, 4×1010Nm2 and 1×1010Nm2 respectively.

The displacement of point B will be

**Q.**Hence, 30. A rocket is fired vertically from the earth with an acceleration of 2g, where g is the gravitationalacceleration. On an inclined plane inside the rocket, making an angle 0 with the horizontal, a point objectof mass m is kept. The minimum coefficient of friction umin between the mass and the inclined surfaceSuch that the mass does not move is(A) tan 20(B) tan 0(C) 3 tan 0(D) 2 tan 0

**Q.**a block of mass m slides down a smooth inclined palne of height h through slope distance s as shown in figure. work done by gravitational force is

**Q.**

Modulus of rigidity is defined as the

ratio of normal stress to tangential strain

ratio of tangential stress to sheer strain

ratio of normal stress to sheer strain

ratio of tangential stress to tangential strain