A steel meter scale is to be ruled so that millimeter intervals are accurate within about $5 \times 10^{-5}$ $mm$ at a certain temperature. The maximum temperature variation allowable during the ruling is .......... $^oC$ (Coefficient of linear expansion of steel $ = 10 \times {10^{ - 6}}{K^{ - 1}})$
$2$
$5$
$7$
$10$
Two metal strips that constitute a thermostat must necessarily differ in their
A thin walled cylindrical metal vessel of linear coefficient of expansion $10^{-3} $ $^o C^{-1}$ contains benzenr of volume expansion coefficient $10^{-3}$ $^o C^{-1}$. If the vessel and its contents are now heated by $10^o C,$ the pressure due to the liquid at the bottom.
A student records the initial length $l$, change in temperature $\Delta T$ and change in length $\Delta l$ of a rod as follows :
S.No. | $l(m)$ | $\Delta T{(^o}C)$ | $\Delta l(m)$ |
$(1)$ | $2$ | $10$ | $4\times 10^{-4}$ |
$(2)$ | $1$ | $10$ | $4\times 10^{-4}$ |
$(3)$ | $2$ | $20$ | $2\times 10^{-4}$ |
$(4)$ | $3$ | $10$ | $6\times 10^{-4}$ |
If the first observation is correct, what can you say about observations $2,\,3$ and $4$.
A solid metallic cube having total surface area $24\;m ^{2}$ is uniformly heated. If its temperature is increased by $10\,^{\circ} C$, calculate the increase in volume of the cube $\left(\right.$ Given $\left.: \alpha=5.0 \times 10^{-4}{ }^{\circ} C ^{-1}\right)$
Two rods of different materials having coefficient of linear expansion $\alpha_1$and $\alpha_2$ and Young's modulii $Y_1$ and $Y_2$ respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If $\alpha_1:\alpha_2= 2 : 3$, the thermal stress developed in two rods are equal provided $Y_1 : Y_2$ is equal to