2
MCQ (Single Correct Answer)
The maximum load a wire can withstand without breaking, when its length is reduced to half of its original length, will
A
be double
B
be half
C
be four times
D
remain same
3
MCQ (Single Correct Answer)
The temperature of a wire is doubled. The Young's modulus of elasticity
A
will also double
B
will become four times
C
will remain same
D
will decrease
4
MCQ (Single Correct Answer)
A spring is stretched by applying a load to its free end. The strain produced in the spring is
A
volumetric
B
shear
C
longitudinal and shear
D
longitudinal
5
MCQ (Single Correct Answer)
A rigid bar of mass $M$ is supported symmetrically by three wires each of length $l$. Those at each end are of copper and the middle one is of iron. The ratio of their diameters, if each is to have the same tension, is equal to
A
$Y_{\text {copper }} / Y_{\text {iron }}$
B
$\sqrt{\frac{Y_{\text {iron }}}{Y_{\text {copper }}}}$
C
$\frac{Y^2{ }_{\text {iron }}}{Y_{\text {copper }}}$
D
$\frac{Y_{\text {iron }}}{Y_{\text {copper }}}$
6
MCQ (Single Correct Answer)
A mild steel wire of length $2 L$ and cross-sectional area $A$ is stretched, well within elastic limit, horizontally between two pillars (figure ). A mass $m$ is suspended from the mid-point of the wire. Strain in the wire is
A
$\frac{x^2}{2 L^2}$
B
$\frac{x}{L}$
C
$x^2 / L$
D
$x^2 / 2 L$