On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because : (1) metals have higher thermal capacity than plastics (2) plastics have a lower density than metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals

On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because : (1) metals have higher thermal capacity than plastics (2) plastics have a lower density than metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals
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metals are good conductors of heat
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On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because – (1) metals have higher thermal capacity than plastics (2) plastics have a lower density than metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals

Description : On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because - (1) metals ... metals (3) metals are good conductors of heat (4) plastics have a higher thermal conductivity than metals

Last Answer : (3) metals are good conductors of heat Explanation: On a chilly day, the room temperature is lower than our body temperature. Since metals have a higher coefficient of thermal conductivity than plastic, they ... from our fingers will flow to the metal cap much more quickly than to the plastic body.

Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to a very high temperature (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation

Description : Pick out the correct statement. (A) Plastics are good conductors of heat and electricity (B) All the polymers are highly crystalline in nature (C) Polymers can be vaporised by heating to ... D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation

Last Answer : (D) The liquid polymer becomes greasy, then waxy and finally solid on increasing the degree of polymerisation

Pick out the wrong statement. (A) Pure rubber is as useless as pure gold as a material of construction (B) Thermal conductivity of aluminium is higher than that of copper; henceit is increasingly used for utensil making(C) Copper has poor weldability(D) Reinforced plastics are made from both thermoplastic as well asthermosetting plastics

Description : Pick out the wrong statement. (A) Pure rubber is as useless as pure gold as a material of construction (B) Thermal conductivity of aluminium is higher than that of copper; henceit is ... has poor weldability (D) Reinforced plastics are made from both thermoplastic as well as thermosetting plastics

Last Answer : (B) Thermal conductivity of aluminium is higher than that of copper; henceit is increasingly used for utensil making

Heat transfer occurs by natural convection because change in temperature causes difference in (A) Viscosity (B) Density (C) Thermal conductivity (D) Heat capacity

Description : Heat transfer occurs by natural convection because change in temperature causes difference in (A) Viscosity (B) Density (C) Thermal conductivity (D) Heat capacity

Last Answer : (B) Density

The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) (A) T (B) 1/T (C) T2 (D) 1/T2

Description : The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) (A) T (B) 1/T (C) T2 (D) 1/T2

Last Answer : A) T

Why a metal bench feels colder than a wooden one.When one sits on it on a cold morning even though both are the same temperature.Explain this observation?

Description : Why a metal bench feels colder than a wooden one.When one sits on it on a cold morning even though both are the same temperature.Explain this observation?

Last Answer : The metal bench is a good thermal heat conductor; since yourbody is warmer than the bench the heat flows rapidly from youwarming the bench and making you feel cold.The wooden bench is apoor ... than thebench your body heat does not flow much by conductivity, so you donot feel much difference.

Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity

Description : Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity

Last Answer : ANSWER: Y -- HIGH MELTING POINT

Plastics are (A) Good conductors of heat. (B) Good conductors of electricity. (C) Bad conductors of electricity. (D) High density.

Description : Plastics are (A) Good conductors of heat. (B) Good conductors of electricity. (C) Bad conductors of electricity. (D) High density.

Last Answer : (C) Bad conductors of electricity.

Heat required to raise the temperature of a body by 1 °C is called its (A) Heat capacity (B) Specific heat capacity (C) Thermal conductivity (D) Water equivalent

Description : Heat required to raise the temperature of a body by 1 °C is called its (A) Heat capacity (B) Specific heat capacity (C) Thermal conductivity (D) Water equivalent

Last Answer : (A) Heat capacity

Metalloids (A) Are good conductor of heat & electricity (B) Act as electron donors with metals & as electron acceptor with non metals (C) Are not necessarily solids at room temperature (D) Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron

Description : Metalloids (A) Are good conductor of heat & electricity (B) Act as electron donors with metals & as electron acceptor with non metals (C) Are not necessarily solids at room temperature ... & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron

Last Answer : D) Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron

A bimetallic strip commonly found in home furnace thermostats works because of the difference in this property of the two metals. Is it: w) thermal shock x) thermal conductivity y) thermal expansion z) thermal diffusivity

Description : A bimetallic strip commonly found in home furnace thermostats works because of the difference in this property of the two metals. Is it: w) thermal shock x) thermal conductivity y) thermal expansion z) thermal diffusivity

Last Answer : ANSWER: Y -- THERMAL EXPANSION

What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Last Answer : (A) 2

A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Description : A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Last Answer : (A) More corrosion resistant

(3) reflection of light due to the presence of free electrons Explanation: Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning "light", and generally implies radiance, gloss, or brilliance. Metals in general have high electrical conductivity, high thermal conductivity, and high density. Typically they are malleable and ductile, deforming -under stress without cleaving.

Description : (3) reflection of light due to the presence of free electrons Explanation: Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word ... conductivity, and high density. Typically they are malleable and ductile, deforming -under stress without cleaving.

Last Answer : Cloud is a colloidal dispersion of – (1) Air in a dispersion medium of water (2) Fog in a dispersion medium of water (3) Mist in a dispersion medium of air (4) Water drops in a dispersion medium of air

With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Description : With increase in temperature, the thermal conductivity of non-metallic amorphous solids (A) Decreases (B) Increases (C) Remain constant (D) First decreases upto certain temperature and then increases

Last Answer : (B) Increases

One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is (A) 100 (B) 900 (C) 9000 (D) 10000

Description : One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is (A) 100 (B) 900 (C) 9000 (D) 10000

Last Answer : (D) 10000

Air over the oceans is colder in summer and warmer in winter compared with air over the continental regions. This is because (a) Water is translucent and has a relatively high heat capacity compared to dirt (b) Compared to dirt, a thicker layer of water participates in the seasonal cycle (c) The albedo of water is greater than that of land and thus reflects more solar radiation (d) Both A and B are true (e) The effect is due to the changes in circulation between continents and oceans

Description : Air over the oceans is colder in summer and warmer in winter compared with air over the continental regions. This is because (a) Water is translucent and has a relatively high heat capacity compared ... B are true (e) The effect is due to the changes in circulation between continents and oceans

Last Answer : (d) Both A and B are true

With increase in temperature, the thermal conductivity of most liquids (A) Increases (B) Decreases (C) Remain same (D) First increases upto a certain temperature and then becomes constant

Description : With increase in temperature, the thermal conductivity of most liquids (A) Increases (B) Decreases (C) Remain same (D) First increases upto a certain temperature and then becomes constant

Last Answer : (C) Remain same

ideal material for making cooking vessels should have (A) High heat capacity (B) Low heat capacity (C) High thermal conductivity (D) Both (B) and (C)

Description : ideal material for making cooking vessels should have (A) High heat capacity (B) Low heat capacity (C) High thermal conductivity (D) Both (B) and (C)

Last Answer : Option D

Which °fine metals has the maximum thermal conductivity? (1) Iron (2) Aluminium (3) Silver (4) Copper

Description : Which °fine metals has the maximum thermal conductivity? (1) Iron (2) Aluminium (3) Silver (4) Copper

Last Answer : (3) Silver Explanation: Silver has the best thermal conductivity of 429 W/mK at RT (295K). It is followed by copper, gold and aluminium. Metals generally have very good electrical conductivity, that leads to high thermal conductivity.

Which of the metals has the maximum thermal conductivity? (1) Iron (2) Aluminium (3) Silver (4) Copper

Description : Which of the metals has the maximum thermal conductivity? (1) Iron (2) Aluminium (3) Silver (4) Copper

Last Answer : Silver

Line losses in a distribution circuit are kept to a minimum by __________. A. adding rubber insulation conductors to the circuit B. using higher current and lower voltage C. increasing the number of thermal relays in the circuit D. using higher voltage and lower current

Description : Line losses in a distribution circuit are kept to a minimum by __________. A. adding rubber insulation conductors to the circuit B. using higher current and lower voltage C. increasing the number of thermal relays in the circuit D. using higher voltage and lower current

Last Answer : Answer: D

The water from a hand pump is warm in winter because - (1) our body is cold in winter and the water appears to be warm (2) the temperature inside the Earth is higher than the atmospheric temperature (3) the pumping process causes friction which warms up the water (4) inside water comes out and absorbs heat from the environment

Description : The water from a hand pump is warm in winter because - (1) our body is cold in winter and the water appears to be warm (2) the temperature inside the Earth is higher than the atmospheric ... causes friction which warms up the water (4) inside water comes out and absorbs heat from the environment

Last Answer : (2) the temperature inside the Earth is higher than the atmospheric temperature

The water from a hand pump is warm in winter because – (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric temperature (3) The pumping process causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Description : The water from a hand pump is warm in winter because - (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric ... causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Last Answer : (2) The temperature inside the earth is higher than the atmospheric temperature Explanation: In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the ... the outside temperature is higher than the water of the pump, and therefore, it feels cold.

The water from a hand pump is warm in winter because – (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric temperature (3) The pumping process causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Description : The water from a hand pump is warm in winter because - (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric ... causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Last Answer : (2) The temperature inside the earth is higher than the atmospheric temperature Explanation: In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the ... the outside temperature is higher than the water of the pump, and therefore, it feels cold.

The water from a hand pump is warm in winter because (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric temperature (3) The pumping process causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Description : The water from a hand pump is warm in winter because (1) Our body is cold in winter and the water appears to be warm (2) The temperature inside the earth is higher than the atmospheric ... causes friction which warms up the water (4) Inside water comes out and absorbs heat from the environment

Last Answer : The temperature inside the earth is higher than the atmospheric temperature

A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides (A) Higher economy (B) Lower capacity (C) Both (A) & (B) (D) Lower economy

Description : A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides (A) Higher economy (B) Lower capacity (C) Both (A) & (B) (D) Lower economy

Last Answer : (A) Higher economy

Solids which conduct electricity at higher temperature but not at lower temperature are called (1) super-conductor (2) metallic-conductor (3) semi-conductor (4) insulator

Description : Solids which conduct electricity at higher temperature but not at lower temperature are called (1) super-conductor (2) metallic-conductor (3) semi-conductor (4) insulator

Last Answer : (3) semi-conductor Explanation: Semiconductors are insulators at low temperatures and reasonably good conductors at higher temperatures. As temperature increases, the semiconductor material becomes a better and better conductor.

Solids which conduct electricity at higher temperature but not at lower temperature are called (1) super-conductor (2) metallic-conductor (3) semi-conductor (4) insulator

Description : Solids which conduct electricity at higher temperature but not at lower temperature are called (1) super-conductor (2) metallic-conductor (3) semi-conductor (4) insulator

Last Answer : semi-conductor

Which solid material has a high heat capacity but low thermal conductivity?

Description : Which solid material has a high heat capacity but low thermal conductivity?

Last Answer : https://en.wikipedia.org/wiki/Thermal_barrier_coating

What is a measure of the ability of a material to conduct heat?  A. Specific heat capacity  B. Coefficient of thermal expansion  C. Coefficient of thermal conductivity  D. Thermal conductivity

Description : What is a measure of the ability of a material to conduct heat?  A. Specific heat capacity  B. Coefficient of thermal expansion  C. Coefficient of thermal conductivity  D. Thermal conductivity

Last Answer : Thermal conductivity

Vycor, a widely used material for making 'thermal wells' in temperature measurement, is a (A) Cermet (B) Glass (C) Thermosetting plastic (D) Metallic alloy

Description : Vycor, a widely used material for making 'thermal wells' in temperature measurement, is a (A) Cermet (B) Glass (C) Thermosetting plastic (D) Metallic alloy

Last Answer : (B) Glass

Plastics as a material of construction suffer from the drawback of low (A) Machinability (B) Density (C) Strength (D) Plastic deformatio

Description : Plastics as a material of construction suffer from the drawback of low (A) Machinability (B) Density (C) Strength (D) Plastic deformatio

Last Answer : Option C

Heat given to a body which raises its temperature by 1°C is known as - (1) water equivalent (2) thermal capacity (3) specific heat (4) temperature gradient

Description : Heat given to a body which raises its temperature by 1°C is known as - (1) water equivalent (2) thermal capacity (3) specific heat (4) temperature gradient

Last Answer : (2) thermal capacity Explanation: Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change.

(a) If the radius of the Br ion is 0.182 nm, how large a cation can fit in each of the tetrahedral hole. (b) AgI crystallizes in a cubic closed packed ZnS structure. What fraction of tetrahedral site is occupied by Ag ion ? (c) At what temp. range, most of the metals becomes super conductors ?

Description : (a) If the radius of the Br ion is 0.182 nm, how large a cation can fit in each of the tetrahedral hole. (b) AgI crystallizes in a cubic closed packed ZnS structure. What fraction of tetrahedral site ... Ag ion ?  (c) At what temp. range, most of the metals becomes super conductors ?

Last Answer : (a) For a tetrahedron the limiting ratio is 0.225 – 0.414 For largest cation highest value 0.414 would be considered. r + / r– = 0.414 r + = 0.414 × 0.182 = 0.075 nm. (b) In FCC there are 8 tetrahedral voids. Out of this ½ is occupied by Ag cation. (c) 2 k – 5 k.

Which of the following variables affects the furnace capacity? (A) Temperature of flue gas (B) Thermal conductivity of stock (C) Thickness of heating stock(D) All (A), (B) and (C)

Description : Which of the following variables affects the furnace capacity? (A) Temperature of flue gas (B) Thermal conductivity of stock (C) Thickness of heating stock (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of thermal conductivity 0.14 W/m.K and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5

Description : A furnace is made of a refractory brick wall of thickness 0.5 metre and thermal conductivity 0.7 W/m.°K For the same temperature drop and heat loss, this refractory wall can be replaced by a layer of diatomaceous earth of ... and thickness __________ metre. (A) 0.01 (B) 0.1 (C) 0.25 (D) 0.5

Last Answer : (B) 0.1

Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above __________ °C, because corrosion prevails at higher temperatures. (A) 350 (B) 750 (C) 1050 (D) 1250

Description : Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above __________ °C, because corrosion prevails at higher temperatures. (A) 350 (B) 750 (C) 1050 (D) 1250

Last Answer : (B) 750

Thermal conductivity of a gas at low density, __________ with increase in temperature. (A) Decreases (B) Increases (C) Remains unchanged (D) May increase or decrease; depends on the gas

Description : Thermal conductivity of a gas at low density, __________ with increase in temperature. (A) Decreases (B) Increases (C) Remains unchanged (D) May increase or decrease; depends on the gas

Last Answer : (B) Increases

Metals are good conductors of electricity because - (1) they contain free electrons (2) the atoms are lightly packed (3) they have high melting point (4) All of the above

Description : Metals are good conductors of electricity because - (1) they contain free electrons (2) the atoms are lightly packed (3) they have high melting point (4) All of the above

Last Answer : (1) they contain free electrons Explanation: Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.

Metals are good conductors of electricity because – (1) they contain free electrons (2) the atoms are lightly packed (3) they have high melting point (4) All of the above

Description : Metals are good conductors of electricity because – (1) they contain free electrons (2) the atoms are lightly packed (3) they have high melting point (4) All of the above

Last Answer : (1) they contain free electrons Explanation: Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points.

Dittus-Boelter equation cannot be used for molten metals mainly due to its very low (A) Prandtl number (B) Grashoff number (C) Thermal conductivity (D) Viscosity

Description : Dittus-Boelter equation cannot be used for molten metals mainly due to its very low (A) Prandtl number (B) Grashoff number (C) Thermal conductivity (D) Viscosity

Last Answer : (A) Prandtl number

A fountain pen works on the principle of (1) Flow of liquids from higher to lower potential (2) Capillary action (3) Bernoulli's principle (4) Viscosity of liquids

Description : A fountain pen works on the principle of (1) Flow of liquids from higher to lower potential (2) Capillary action (3) Bernoulli's principle (4) Viscosity of liquids

Last Answer : (2) Capillary action Explanation: A fountain pen is a nib pen that, unlike its predecessor the dip pen, contains an internal reservoir of water-based liquid ink. The pen draws ink from the ... to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity.

A fountain pen works on the principle of (1) flow of liquids from higher to lower potential (2) capillary action (3) Bernoulli’s principle (4) Viscosity of liquids

Description : A fountain pen works on the principle of (1) flow of liquids from higher to lower potential (2) capillary action (3) Bernoulli’s principle (4) Viscosity of liquids

Last Answer : capillary action

The snow on the mountains does NOT melt all at once when it is heated by the sum because: (1) It becomes very hard (2) It reflects most of the heat from the sum (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Description : The snow on the mountains does NOT melt all at once when it is heated by the sum because: (1) It becomes very hard (2) It reflects most of the heat from the sum (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Last Answer : (2) It reflects most of the heat from the sum Explanation: Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when ... on a spring day because of the sun's heat. It melts because of the warm air from the sea.

The snow on the mountains does NOT melt all at once when it is heated by the sun because: (1) it becomes very hard (2) it reflects most of the heat from the sun (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Description : The snow on the mountains does NOT melt all at once when it is heated by the sun because: (1) it becomes very hard (2) it reflects most of the heat from the sun (3) it has a low specific heat capacity (4) it has a high latent heat of fusion

Last Answer : it reflects most of the heat from the sun

Which of the following criterion is used for any metal to be used as a cooking material? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Description : Which of the following criterion is used for any metal to be used as a cooking material? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Last Answer : (3) Less thermal conductivity Explanation: A metal to be used as a cooking material should have less thermal conductivity.

Which of the following criterion is used for any metal to be used as a cooking material ? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Description : Which of the following criterion is used for any metal to be used as a cooking material ? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Last Answer : Less thermal conductivity 

The density of seawater is greater than that of fresh water. A boat will float: w) Higher in fresh water than in seawater x) Lower in fresh water than in seawater y) At the same level in both z) Any of the above, depending upon its shape

Description : The density of seawater is greater than that of fresh water. A boat will float: w) Higher in fresh water than in seawater x) Lower in fresh water than in seawater y) At the same level in both z) Any of the above, depending upon its shape

Last Answer : ANSWER: X -- LOWER IN FRESH WATER THAN IN SEAWATER

A steel ball floats on mercury because (a) mercury does not allow any metallic ball to sink in it (b) mercury is also a metal in the liquid form (c) the density of mercury is higher than that of steel (d) a steel ball can be made to float on any liquid by suitable adjustment

Description : A steel ball floats on mercury because (a) mercury does not allow any metallic ball to sink in it (b) mercury is also a metal in the liquid form (c) the density of mercury is higher than that of steel (d) a steel ball can be made to float on any liquid by suitable adjustment

Last Answer : Ans:(c)