The temperature of a wire is doubled. The Young's modulus of elasticity

A spring is stretched by applying a load to its free end. The strain produced in the spring is

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 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 rectangular frame is to be suspended symmetrically by two strings of equal length on two supports (figure). It can be done in one of the following three ways;

The tension in the strings will be