Properties of Matter

The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is

A certain number of spherical drops of a liquid of radius r coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

Steam at 100oC is passed into 20 g of water at 10oC. When water acquires a temperature of 80oC, the mass of water present will be
[Take specific heat of water = 1 cal g\(-\)1 oC\(-\)1 and latent heat of steam = 540 cal g\(-\)1]

Copper of fixed volume V is drawn into wire of length \(l\). When this wire is subjected to a constant force F, the extension produced in the wire is \(\Delta\)\(l\). Which of the following graphs is a straight line ?

Certain quantity of water cools from 70oC to 60oC in the first 5 minutes and to 54oC in the next 5 minutes. The temperature of the surroundings is

Two metal rods 1 and 2 of same lengths have same temperature difference between their ends. Their thermal conductivities are K1 and K2 and cross sectional areas A1 and A2, respectively. If the rate of heat conduction in 1 is four times that...

If the ratio of diameters, lengths and Young's modulus of steel and copper wires shown in the figure are p, q and s respectively, then the corresponding ratio of increase in their lengths would be

A fluid is in streamline flow across a horizontal pipe of variable area of cross section. For this which of the following statements is correct?

The density of water at 20oC is 998 kg/m3 and at 40oC is 992 kg/m3. The coefficient of volume expansion of water is

A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The correct explanation for the above observation is possible by using

The molar specific heats of an ideal gas at constant pressure and volume are denoted by Cp and Cv, respectively. If  \(\gamma\) = \({{{C_p}} \over {{C_v}}}\) and R is the universal gas constant, then Cv is equal to

The following four wires are made of the same material. Which of these will have the largest extension when the same tension is applied?

The wettability of a surface by a liquid depends primarily on

If the radius of a star is R and it acts as a black body, what would be the temperature of the star, in which the rate of energy production is Q?

Liquid oxygen at 50 K is heated to 300 K at constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time ?

A slab of stone of area 0.36 m2 and thickness 0.1 m is exposed on the lower surface to steam at 100oC. A block of ice at 0oC rests on the upper surface of the slab. In one hour 4.8 kg of ice is melted. The thermal conductivity of slab is
(G...

A cylindrical metallic rod in thermal contact with two reservoirs of heat at its two ends conducts an amount of heat Q in time t. The metallic rod is melted and the material is formed into a rod of half the radius of the original rod. What ...

The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of radius r, whose outer surface radiates as a black body at a temperature TK is given by

Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature toC, the power received by a unit surface, (normal to the incident rays) at a distance R from the centre of the sun is
where $$\sigm...

A black body at 227oC radiates heat at the rate of 7 cals/cm2s. At a temperature of 727oC, the rate of heat radiated in the same units will be

The two ends of a rod of length L and a uniform cross-sectional area A are Kept at two temperatures T1 and T2 (T1 > T2). The rate of heat transfer, \({{dQ} \over {dt}}\) through the rod in a steady state is given by :

On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are 39oW and 239oW respectively. What will be the temperature on the new scale, corresponding to a temperature of 39oC on the ...

A black body is at 727oC. It emits energy at a rate which is proportional to

Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature toC, the power received by a unit surface, (normal to the incident rays) at a distance R from the centre of the sun is
where $$\sigm...

A black body at 1227oC emits radiations with maximum intensity at a wavelength of 5000 \(\mathop A\limits^ \circ\). If the temperature of the body is increased by 1000oC, the maximum intensity will be observed at

Which of the following rods, (given radius r and length \(l\)) each made of the same material and whose ends are maintained at the same temperature will conduct most heat ?

If \(\lambda\)m denotes the wavelength at which the radioactive amission from a black body at a temperature TK is maximum, then

Consider a compound slab consisting of two different materials having equal thicknesses and thermal conductivities K and 2K, respectively. The equivalent thermal conductivity of the slab is

Unit of Stefan's constant is

The Wien's displacement law express relation between

Which of the following is best close to an ideal black body?

Consider two rods of same length and different specific heats (S1, S2), conductivities (K1, K2) and area of cross-sections (A1, A2) and both having temperatures T1 and T2 at their ends. If rate of loss of heat due to conduction is equal, th...

For a black body at temperature 727oC, its radiating power is 60 watt and temperature of surrounding is 227oC. If temperature of black body is changed to 1227oC then its radiating power will be

A cylindrical rod having temperature T1 and T2 at its end. The rate of flow of heat Q1 cal/sec. If all the linear dimension are doubled keeping temperature constant, then rate of flow of heat Q2 will be

A black body has maximum wavelength \(\lambda\)m at 2000 K. Its corresponding wavelength at 3000 K will be