Physics

Deformation of Solid

Answer all questions within the time provided

Multiple Choice

A copper wire hangs vertically from a fixed point. A load is attached to the lower end of the wire

producing an extension x. The wire obeys Hooke’s law.

Which single change gives an extension 2x?

• Halve the cross-sectional area of the wire.

• Halve the diameter of the wire.

• Halve the length of the wire.

• Halve the load on the wire.

Multiple Choice

A wire is stretched by a force F so that it experiences an extension of x. The energy stored in the wire is $\frac{1}{2}Fx$ only if  

• the elastic limit of the wire is not exceeded

• the tensile force is proportional to the extension

• the weight of the wire is neglected

• the cross sectional area of the wire does not change

Multiple Choice

a steel wire has original length l, cross-sectional area A, and Young modulus Y. The force constant of the wire can be expressed as

• $\frac{AY}{l}$

• $\frac{Al}{Y}$

• $\frac{Y}{Al}$

• $\frac{l}{AY}$

Multiple Select

Which of the following does not influence the strain of a wire when a vertical wire of uniform diameter is stretched at its lower end?

• Young modulus

• cross-sectional area

• original length

• stress

Multiple Choice

A metal wire is stretched by a load. The force-extension graph is shown.

• the change in gravitational potential energy of the wire

• the energy that would be released from the wire if the final load was removed

• the energy transferred into heat energy in the wire

• the work done in stretching the wire

Multiple Choice

A spring pulled by a force of 10 N, produces an extension of 40 mm. Two identical springs arranges in series produce a total extension of 40 mm. What is the energy stored in the two springs?

• 0.05 J

• 0.10 J

• 0.15 J

• 0.20 J

Multiple Choice

A material that can be drawn into wire

• malleable

• ductile

• strong

• brittle

Multiple Choice

The tension of a stretched wire is given by $T=\frac{\lambda}{l}$   with  $\Delta x$  as the extension,  $l$  as the original length of the wire and  $\lambda$  as a constant. If the cross sectional area is  $A$  ,the expression of Young modulus of the wire is

•  $\frac{\lambda}{A}$  

•   $\frac{\lambda}{A\Delta x}$  

•  $\frac{\lambda}{l}$  

•  $\frac{Al}{\Delta x}$  

Fill in the Blanks

Multiple Select

The following quantities are required to calculate Young modulus

• initial length

• Force applied to material

• diameter of the material

• Mass of the material