The scale on a steel metre stick is calibrated at $20^{\circ}C$. The error in the reading of $50 \, cm$ at $30^{\circ}C$ is: (take linear expansion coefficient of steel $\alpha = 1.0 \times 10^{-5} / ^{\circ}C$)

$A$ seconds pendulum clock has a steel wire. The clock shows correct time at $25^{\circ} C$. How many seconds does the clock lose or gain in one week,when the temperature is increased to $35^{\circ} C$? (Given: $\alpha_{\text{steel}} = 1.2 \times 10^{-5} /^{\circ} C$)

$A$ non-isotropic solid metal cube has coefficients of linear expansion as:
$5 \times 10^{-5} /^{\circ} C$ along the $x$-axis and $5 \times 10^{-6} /^{\circ} C$ along the $y$ and the $z$-axis. If the coefficient of volume expansion of the solid is $C \times 10^{-6} /^{\circ} C$,then the value of $C$ is:

Three rods of equal lengths are joined to form an equilateral triangle $ABC$. $D$ is the mid-point of $AB$. The coefficient of linear expansion is $\alpha_1$ for the material of rod $AB$ and $\alpha_2$ for the material of rods $AC$ and $BC$. If the distance $DC$ remains constant for small changes in temperature, then:

Two rods,one made of aluminium and the other made of steel,having initial lengths $l_1$ and $l_2$ respectively,are connected together to form a single rod of length $(l_1 + l_2)$. The coefficients of linear expansion for aluminium and steel are $\alpha_1$ and $\alpha_2$ respectively. If the length of each rod increases by the same amount when their temperature is raised by $t^oC$,then the ratio $l_1/(l_1 + l_2)$ is:

Two large holes are cut in a metal sheet. If this sheet is heated,what happens to the distances $AB$ and $BC$ as shown in the figure?