Thermal properties of matter practice · Easy

A wire of cross sectional area $4\,m{m^2}$ is fixed between two points at ${30^ \circ }C.Y = 2 \times {10^{11}}pa$ and $\alpha = {10^{ - 5}}/\,{\,^ \circ }C$ ; When the temperature falls to ${20^ \circ }C$ , the tension in the string in (newton) is

The temperature of the two ends A and B of a rod of length 25 cm and circular cross section are $100^\circ C$ and $0^\circ C$ respectively. In the steady state, the temperature at a distance of 10cm from end B (ignore loss of heat from curved surface of the body is)

Red, yellow $\&$ black color objects are heated up to same temperature and taken dark room. Which will glow brightest

Ratio among linear expansion coefficient $(\alpha )$ areal expansion coefficient $(\beta )$ and volume expansion coefficient $(\gamma )$ is

Two iron rods have their lengths in the ratio 5:3 and diameters in ratio 2:1 when the rods are heated from ${30^ \circ }C$ to ${100^ \circ }C$the ratio of their linear expansions is

A correct thermometer in Fahrenheit is introduced in a water bath along with a Celsius thermometer. The reading observed are ${86^ \circ }F$ and ${32^ \circ }C$ the correction to be made to the Celsius reading will be

When the room temperature becomes equal to the dew point, the relative humidity of the room is

Air is filled at $60^{\circ} \mathrm{C}$ in a vessel of open mouth. The vessel is heated to a temperature $T$ so that $1 / 4^{\text {th}}$ part of air escapes. Assuming the volume of the vessel remaining constant, the value of $T$ is

At $0^{\circ} \mathrm{C}$, the densities of a cork and a liquid in which the cork floats are $\mathrm{d}_1$ and $\mathrm{d}_2$ respectively. The coefficients of expansion for the material of the cork and the liquid are $\gamma$ and $100 \gamma$ respectively. If the cork sinks when temperature of liquid is $\mathrm{t}^{\circ} \mathrm{C}$, then ratio $\left(\mathrm{d_2 / d}_1\right)$ is

The lower and upper fixed points in Reaumur scale is

The maximum wavelength in the energy distribution spectrum of sun is $4753\,\,\mathop {\text{A}}\limits^ \circ$ and its temperature is $6050 \mathrm{~K}$. The temperature of star whose energy distribution shows a maximum at $9506\,\,\mathop {\text{A}}\limits^ \circ$ is

The standard fixed point for temperature measurements in use today is