## MCQ (Single Correct Answer)

Two copper vessels A and B have the same base area but of different shapes. A takes twice the volume of water as that B requires to fill upto a partic...

The terminal velocity of a copper ball of radius 5 mm falling through a tank of oil at room temperature is 10 cm s$$-$$1. If the viscosity of oil at r...

A spherical ball is dropped in a long column of a highly viscous liquid. The curve in the graph shown, which represents the speed of the ball (v) as a...

If a soap bubble expands, the pressure inside the bubble

Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The stretching of a spring ...

The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerin becomes constant after some time. If the densit...

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillar...

A wire of length L, are of cross section A is hanging from a fixed support. The length of the wire changed to L1 when mass M is suspended from its fre...

A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in tmperature. The length of alumin...

When a block of mass M is suspended by a long wire of length L, the length of the wire becomes (L + $$l$$). The elastic potential energy stored in the...

A small hole of area of cross-section 2 mm2 present near the bottom of a fully filled open tank of height 2 m. Taking g = 10 m/s2, the rate of flow o...

The unit of thermal conductivity is :

A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of 2.5 $$ \times $$ 10–2 N/m. The pressure inside th...

The power radiated by a black body is P and it
radiates maximum energy at wavelength, $$\lambda $$0
. If
the temperature of the black body is now
chan...

Two wires are made of the same material and
have the same volume. The first wire has
cross-sectional area A and the second wire has
cross-sectional ar...

A small sphere of radius ‘r’ falls from rest in a
viscous liquid. As a result, heat is produced
due to viscous force. The rate of production of
heat w...

The bulk modulus of a spherical object is 'B'. If it is subjected to uniform pressure 'P', the fractional decrease in radius is

A U tube with both ends open to the atmosphere, is partially filled with water. Oil, which is immiscible with water, is poured into one side until it...

A spherical black body with a radius of 12 cm radiates 450 watt power at 500 K. If the radius were halved and the temperature doubled, the power radia...

Two rods A and B of different materials are welded together as shown in figure. Their thermal conductivities are K1 and K2. The thermal conductivity o...

A body cools from a temperature 3T to 2T in 10 minutes. The room temperature is T. Assume that Newton's law of cooling is applicable. The temperature ...

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is at 100oC, while the other one is a...

A rectangular film of liquid is extended from (4 cm $$ \times $$ 2 cm) to (5 cm $$ \times $$ 4 cm). If the work done is 3 $$ \times $$ 10$$-$$4 J, the...

Three liquids of densities $$\rho $$1, $$\rho $$2 and $$\rho $$3 (with $$\rho $$1 > $$\rho $$2 > $$\rho $$3), having the same value o...

Coefficient of linear expansion of brass and steel rods are $$\alpha $$1 and $$\alpha $$2. Lengths of brass and steel rods are $$l$$1 and $$l$$2 respe...

A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice g...

Two non-mixing liquids of densities $$\rho $$ and n$$\rho $$ (n > 1) are put in a container. The height of each liquid is h. A solid cylinder of le...

A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is U1, at wavelength 500 nm is U2 and tha...

The value of coefficient of volume expansion of glycerin is 5 $$ \times $$ 10$$-$$4 K$$-$$1. The fractional change in the density of glycerin for a ri...

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, t...

Water rises to a height h in capillary tube. If the length of capillary tube above the surface of water is made less than h, then

The Young's modulus of steel is twice that of brass. Two wires of same length and of same area of cross section, one of steel and another of brass are...

The two ends of a metal rod are maintained at temperatures 100oC and 110oC. The rate of heat flow in the rod is found to be 4.0 J/s. If the ends are m...

A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is 250 m2. Assuming that the pressure inside the house is atmosph...

On observing light from three different starts P, Q and R, it was found that intensity of violet colour is maximum in the spectrum of P, the intensity...

The approximate depth of an ocean is 2700 m. The compressiblity of water is 45.4 $$ \times $$ 10$$-$$11 Pa$$-$$1 and density of water is 103 kg/m3. Wh...

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 ...

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 th...

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 ...

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 secti...

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 correspondi...

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 fo...

The molar specific heats of an ideal gas at constant pressure and volume are denoted by Cp and Cv, respectively. If $$\gamma $$ = $${{{C_p}} \ov...

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

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 surfac...

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 ...

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?

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 ...

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 ou...

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, ...

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,...

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. Wha...

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, ...

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

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 i...

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 wi...

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 equival...

Unit of Stefan's constant is

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...

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 te...

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

The Wien's displacement law express relation between

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 temper...

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