Properties of Bulk matter

A slab consists of two parallel layers of two different materials of same thickness and area having thermal conductivities K₁ and K₂. The equivalent conductivity of the combination of

If capillary experiment is performed in vaccum, then a liquid under the condition

Cohesive force is experienced between

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

A body, which emits radiations of all possible wavelengths, is known as

The pressure at the bottom of a tank containing a liquid does not depend on

The wetability of a surface by a liquid depends primarily on

If liquid level falls in a capillary then radius of capillary will 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?

In a capillary tube water raises by 1.2 mm. The height of water that will rise in another capillary tube having half the radius of the first will be

Oil spreads over the surface of water where as water does not spread over the surface of the oil because

When two small bubbles join to form a bigger one, energy is

The length of an elastic string is a metre when the longitudinal tension is 4N and b metre when the longitudinal tension is 5N. The length of the string on metre when the longitudinal tension is 9 N is

The original temperature of a black body is 727⁰C. The temperature at which this black body must be raised so as to double the total radiant energy is

According to Hook’s law of elasticity, if stress is increased, the ratio of stress to strain

A metal bar of length L and area of cross-section A is clamped between two rigid supports. For the material of the rod, Young’s modulus is Y and coefficient of linear expansion is α. If the temperature of the rod is increased by ∆t⁰C, the force exerted by the rod on the supports is

Stress to strain ratio is equivalent to

Which is correct relation?

Which of the following is true for elastic potential energy density?

Which of the following statements is correct?

If the interatomic spacing in a steel wire is 3.0 Å and Y of steel is 20 x 10¹⁰ N/m², then force constant is

A body of length 1 m having cross-sectional area 0.75 m² has heat flow through it at the rate of 6000 joule/sec. Then find the temperature difference if K=200 Jm⁻¹K⁻¹

A body is placed in an insulating container at temperature 227⁰C. In order to keep its temperature at 727⁰C, power of 60 watt is required. Then power required to keep its temperature at 1227⁰C will be

A black body is at 727⁰C. It emits energy at a rate which is proportional to

If the cold junction of a thermo-couple is kept at 0⁰C and the hot junction is kept at T⁰C then the relation between neutral temperature (Tₙ) and temperature of inversion (Ti) is

An ideal black body is equivalent to

Assuming the sun to have a spherical outer surface of radius r, radiating like a black body at temperature t⁰C, the power received by a unit surface, (normal to the incident rays) at a distance R from the centre of the sun is

An electric kettle takes 4A current at 220V. How much time will it take to boil 1 kg of water from temperature 20⁰C? The temperature of boiling water is 100⁰C.

A body takes 5 minute for cooling from 50⁰C to 40⁰C. Its temperature comes down to 33.33⁰C in next 5 minute. Temperature of surroundings is

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/dt through the rod in a steady state is given by:

A black body at 227⁰C radiates heat at the rate of 7 cals/cm²s. At a temperature of 727⁰C, the rate of heat radiated in the same units will be:

A liquid wets a solid completely. The meniscus of the liquid in a sufficiently long tube is

Heat is flowing through a rod of length 50 cm and area of cross-section 5 cm². Its ends are respectively at 25⁰C and 125⁰C. The coefficient of thermal conductivity of the rod is 0.092 k.cal/m x s x ⁰C. The temperature gradient in the rod is

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 T K is given by: (where σ is Stefan’s constant)

Water rises in a vertical capillary tube up to a height of 2.0 cm. If the tube is inclined at an angle of 60⁰ with the vertical, then up to what length the water will rise in the tube?

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

A black body radiates 20 W at temperature 227⁰C. It temperature of the black body is changed to 727⁰C, then its radiating power will be

Shearing stress causes change in

The area of cross-section of a steel wire (Y=2.0×10¹¹ N/m²) is 0.1 cm². The force required to double its length will be

The maximum wavelength of radiations emitted at 900 K is 4 µm. What will be the maximum wavelength of radiations emitted at 1200 K?

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

A uniform plank of Young’s modulus Y is moved over a smooth horizontal surface by a constant horizontal force F. The area of cross-section of the plank is A. The compressive strain on the plank in the direction of the force is

The temperature of a body falls from 50⁰C to 40⁰C in 10 minute. If the temperature of the surroundings is 20⁰C, then temperature of the body after another 10 minute will be

The molar specific heats of an ideal gas at constant pressure and volume are denoted by Cp and Cv, respectively. If γ = Cp/Cv and R is the universal gas constant, then Cv is equal to

The breaking stress of a wire depends upon

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 rod 1 is four times that in rod 2, then

According to Hook’s law, force is proportional to

In the Young’s modulus experiment, if length of wire and radius both are doubled, then the value of Y will becomes

Which of the following is an example of ideal black body?

A wire of length 2 m is made from 10 cm³ of copper. A force F is applied so that its length increases by 2 mm. Another wire of length 8 m is made from the same volume of copper. If the force F is applied to it, its length will increase by

Young’s modulus of perfectly rigid body material is

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

The earth radiates in the infrared region of the spectrum. The spectrum is correctly given by

Two bubbles A and B (A>B) are joined through a narrow tube. Then

Radius of a soap bubble is increased from R to 2R. Work done in this process in terms of surface tension S is

The temperature of a metal block is increased from 27⁰C to 84⁰C. The rate of radiated energy from the block will increase approximately

Application of Bernoulli’s theorem can be seen in

If two soap bubbles of different radii are connected by a tube

A cylindrical tank is filled with water to a level of 3m. A hole is opened at a height of 52.5 cm from bottom. The ratio of the area of the hole to that at cross sectional area at cylinder is 0.1. Find the square of the velocity with which water is coming out (g=10 m/sec²)

A spherical body of emissivity e=0.6, placed inside a perfectly black body is maintained at temperature T then the energy radiated per second will be

Angle of contact of a liquid with a solid depends on

In which of the following heat loss is primarily not due to convection?

When the temperature increases, the viscosity of

In a surrounding medium of temperature 10⁰C a body takes 7 min for a fall of temperature from 60⁰C to 40⁰C. In what time the temperature of the body will fall from 40⁰C to 28⁰C?

Ice is wrapped in black and white cloth. In which cases more ice will melt

If h is the height of the capillary rise and r be the radius of capillary tube, then which of the following relation will be correct?

A body of mass 120 kg and density 600 kg/m³ floats in water. What additional mass could be added to the body so that the body will just sink?

Three objects coloured black, gray and white can withstand hostile conditions upto 2800⁰C. These objects are thrown into a furnace where each of them attains a temperature of 2000⁰C. Which object will glow brightest?

If a spring of spring constant k stretched by a length x under tension T, the energy stored is

A body is under stress F and has Young’s modulus Y, then the energy stored per unit volume equals to

The surface temperature of the sun which has maximum energy emission at 500 nm is 6000 K. The temperature of a star which has maximum energy emission at 400 nm will be

If a small sphere is let fall vertically in a large quantity of still liquid of density smaller than that of the material of the sphere

A pan is suspended from a steel wire. Weights are slowly put on the pan and as the weight increases, the change in the length of the steel wire

A polished metal plate has a rough and black-spot. It is heated to 1400 K and brought immediately in dark room. Then

A bimetallic strip consists of metals X and Y. It is mounted rigidly at the base as shown. The metal X has a higher coefficient of expansion compared to that for metal Y. When the bimetallic strip is placed in a cold bath

A wire elongates by l mm when a load W is hanged from it. If the wire goes over a pulley and two weights W each are hung at the two ends, the elongation of the wire will be (in mm)

A layer of glycerine of thickness 1 mm present between a large surface area of 0.1 m². With what force the small surface is to be pulled, so that it can move with a velocity 1 m/s, given that the coefficient of viscocity =0.07 kg m⁻¹ s⁻¹

Water flows through a pipe. The area of cross-section at one place A₁=10 cm², velocity of flows 1 m/s and pressure 2000 Pa. At another place area A₂=5 cm². What is the pressure at area A₂=5 cm²?

Which of the following rods of same material undergoes maximum elongation when subjected to a given force?

The surface tension of a liquid is 5 newton per metre. If a film is held on a ring of area 0.02 metre², its surface energy is about

Surface tension of water will be minimum at

In old age arteries carrying blood in the human body become narrow resulting in an increase in the blood pressure. This follows from

Work of 3.0×10⁻⁴ joule is required to be done in increasing the size of a soap film from 10cm x 6cm to 10cm x 11cm. The surface tension of the film is

If the volume of a block of aluminium is decreased by 1%, the pressure (stress) on its surface is increased by (Bulk modulus of Al=7.5×10¹⁰ Nm⁻²)

The area of cross-section of one limb of an U-tube is twice that of the other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by 1 cm. The height of water column is (density of water =10³ kg m⁻³, density of mercury=13.6 x 10⁻³ kg m⁻³)

A wire is stretched under a force. If the wire suddenly snaps the temperature of the wire

Which of the following substances has the highest elasticity?

The surface tension of soap solution is 0.03 N/m. The work done in blowing to form a soap bubble of surface area 40 cm², in joules is

A spherical liquid drop of radius R is divided into 8 equal droplets. If the surface tension is T, then work done in the process will be