The graph AB shown in figure is a plot of the temperature of a body in degree Celsius and degree Fahrenheit. Then,

       
 

1.	slope of line AB is \(9/5\)
2.	slope of line AB is \(5/9\)
3.	slope of line AB is \(1/9\)
4.	slope of line AB is \(3/9\)

The fundamental interval, that is the number of division between LFP & UFP on the two scales X and Y are 50 and 150 respectively. The ice point on both the scales is  $0°$. If the temperature on the X-scale is $15°$, then what is the temperature on the Y-scale ?

$1. 30°$
$2. 45°$
$3. 60°$
$4. 75°$

In which of the following phenomenon heat convection does not take place

1. land and sea breeze

2. boiling of water

3. heating of glass surface due to filament of the bulb

4. air around the furnace

A copper rod of \(88\) cm and an aluminium rod of an unknown length have an equal increase in their lengths independent of an increase in temperature. The length of the aluminium rod is:
\(\left(\alpha_{Cu}= 1.7\times10^{-5}~\text{K}^{-1}~\text{and}~\alpha_{Al}= 2.2\times10^{-5}~\text{K}^{-1}\right)\)
1. \(68~\text{cm}\)
2. \(6.8~\text{cm}\)
3. \(113.9~\text{cm}\)
4. \(88~\text{cm}\)

Which of the following statement is correct regarding heat transfer?

1.  Forced convection requires gravity

2.  Natural convection requires gravity

3.  Radiation and forced convection requires gravity

4.  Neither natural nor forced convection requires gravity

An object kept in a large room having an air temperature of \(25^\circ \text{C}\) takes \(12\) minutes to cool from \(80^\circ \text{C}\) to \(70^\circ \text{C}.\) The time taken to cool for the same object from \(70^\circ \text{C}\) to \(60^\circ \text{C}\) would be nearly:
1. \(10\) min
2. \(12\) min
3. \(20\) min
4. \(15\) min

A deep rectangular pond of surface area A, containing water (density = \(\rho,\) specific heat capacity = \(s\)), is located in a region where the outside air temperature is at a steady value of \(-26^{\circ}\mathrm{C}\)$$. The thickness of the ice layer in this pond at a certain instant is \(x\). Taking the thermal conductivity of ice as \(k\), and its specific latent heat of fusion as \(L\), the rate of increase of the thickness of the ice layer, at this instant, would be given by:
1. \(\frac{26k}{x\rho L-4s}\)
2. \(\frac{26k}{x^2\rho L}\)
3. \(\frac{26k}{x\rho L}\)
4. \(\frac{26k}{x\rho L+4s}\)

A black body at 1227 °C emits radiations with maximum intensity at a wavelength of 5000 Å. If the temperature of the body is increased by 1000 °C, the maximum intensity will be observed at:

1. 4000 Å

2. 5000 Å

3. 6000 Å

4. 3000 Å

A black body is at 727 °C. It emits energy at a rate that is proportional to:

1. $(727{)}^2$

2. $(1000{)}^4$

3. $(1000{)}^2$

4. $(727{)}^4$

Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature t °C, the power received by a unit surface of the earth (normal to the incident rays) at a distance R from the centre of the sun is: 
(where σ is Stefan’s constant.)

1. $\frac{4{\mathrm{\pi r}}^2{\mathrm{\sigma t}}^4}{R^2}$

2. $\frac{r^2\sigma (t+273{)}^4}{4\mathrm{\pi }{R}^2}$

3. $\frac{16{\pi }^2{r}^2{\mathrm{\sigma t}}^4}{R^2}$

4. $\frac{r^2\sigma (t+273{)}^4}{R^2}$