Description : When iron rusts, its weight – (1) decreases (2) increases (3) remains the same (4) first increases and then decreases
Last Answer : (2) increases Explanation: When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water and the metal. Because of the oxygen atoms binding with the metal, the weight of the metal with rust will increase.
Description : When iron rusts, its weight : (1) decreases (2) increases (3) remains the same (4) first increases and then decreases
Last Answer : (2) increases Explanation: When iron rusts, oxide compounds are formed due the interaction between oxygen in the air or in water an the metal.
Description : When iron rusts, its weight (1) decreases (2) increases (3) remains the same (4) first increases and then decreases
Last Answer : increases
Description : When iron rusts, the weight (a) Increases (b) Decreases (c) Remains the same (d) First increases then decreases
Last Answer : Ans:(a)
Description : When iron rusts, how is its weight? -Do You Know?
Last Answer : answer:
Description : When iron rusts, how is its weight?
Last Answer : – Increases
Description : When Iron rusts; its weight?
Last Answer : Increases
Description : What is meant by ‘rusting’? With labelled diagrams, describe an activity to find out the conditions under which iron rusts. -Chemistry
Last Answer : When iron is exposed to air and moisture for a very long time, it gets covered with a brown flaky substance. This brown flaky substance is called rust and the process is called rusting. The ... when only oxygen was available, it shows that rusting cannot take place if only oxygen is available.
Description : Iron rusts quickly in – (1) Rain water (2) Sea water (3) Distilled water (4) River water
Last Answer : (2) Sea water Explanation: Water is the enabler of fast oxidation of iron. So freshwater will also cause rust. However, salt water (sea water) is a very good conductor (lots of dissociated ions ... which causes the current to be re-versed and in effect the zinc corrodes rapidly, protecting the iron.
Description : Iron rusts quickly in (1) Rain water (2) Sea water (3) Distilled water (4) River water
Last Answer : Sea water
Description : Of the following processes in nature, which one involves only a physical change A. A bird digests a worm. B. Photosynthesis occurs in a leaf. C. An earthquake causes a rockslide. D. A chunk of iron ore rusts.?
Last Answer : C: An Earthquake causes a rockslide
Description : Iron rusts at the area (a) Cathodic area (b) Anodic area (c) Both cathodic and anodic areas (d) None of the above
Description : Iron rusts quickly in
Description : A chemical change takes place when iron (A) Rusts (B) Melts (C) Is heated (D) None of these
Last Answer : (A) Rusts
Description : Give reason: a) Iron exposed to air rusts quickly during rainy season.
Last Answer : a) Iron exposed to air rusts quickly during rainy season. Due to the presence of excess water vapour. b) Iron nail kept in a closed jar containing calcium chloride does not rust. As air is dry ... ) Tin is used to coat the inner walls of brass and copper utensils. To avoid corrosion or rusting.
Description : . Iron rusts quickly in
Description : C.V. (kcal/Nm3 ) of gaseous fuels __________ with increase in molecular weight. (A) Decreases (B) Increases (C) Remain constant (D) May increase or decrease, depends on combustibles
Last Answer : (D) May increase or decrease, depends on combustibles
Description : Due to a rise in temperature, the viscosity and the unit weight of the percolating fluid are reduced to 60% and 90% respectively. If other things remain constant, the coefficient of permeability (A) Increases by 25 % (B) Increases by 50 % (C) Increases by 33.3 % (D) Decreases by 33.3 %
Last Answer : (B) Increases by 50 %
Description : Due to rusting the weight of iron - (1) Decreases (2) Increases (3) Remains the same (4) Uncertain
Last Answer : (2) Increases Explanation: Corrosion of a block of metal - Iron to Iron Oxide (rust), Aluminum to Bauxite, Cooper to Cupric-oxide, or otherwise - does not change the weight of the metal in the system.
Description : The threshold frequency is the frequency below which – (1) photo current increases with voltage (2) photo current decreases with voltage (3) photo electric emission is not possible (4) photo current is constant
Last Answer : (3) photo electric emission is not possible Explanation: The photoelectric effect is the emission of electrons by substances, especially metals, when light falls on their surfaces. The photoelectric ... gain sufficient energy to overcome the electrostatic barrier of the work function of the metal.
Description : The threshold frequency is the frequency below which - (1) photo current is constant (2) photo current increases with voltage (3) photo current decreases with volt (4) photo electric emission is not possible
Last Answer : (4) photo electric emission is not possible
Description : As the molecular weight of alkanes increases, how do the boiling point and melting point change? (a) boiling point increases ; melting point increases. (b) boiling point increases ; ... decreases (d) boiling point increases ; melting point increases sequentially for alkanes over four carbons.
Last Answer : boiling point increases ; melting point increases sequentially for alkanes over four carbons.
Description : As the temperature of ice rises, the ice melts and its density _____. A. Decreases B. Remains constant C. Increases D. Increases upto 10 °C
Last Answer : ANSWER: C
Description : When water freezes its density – (1) Decreases (2) Becomes Zero (3) Remains constant (4) Increases
Last Answer : (1) Decreases Explanation: Water at ordinary temperatures contracts and in-creases in density as it is cooled, like most substances. But at about 4°C it reaches a maximum density and then decreases in density as it approaches the freezing point. This is referred to as anomalous property of water.
Description : At boiling point of liquids, its – (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases
Last Answer : (3) Temperature remains constant Explanation: An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point.
Description : When a detergent is added to pure water, its surface tension – (1) increases (2) decreases (3) remains constant (4) becomes infinite
Last Answer : (2) decreases Explanation: When Soaps and detergents are added to water, they weaken the strength of the skin on the water's surface due to surface tension by interfering with hydrogen bonding ... of the soap or detergent is also attracted to the water, thereby decreasing the surface tension.
Description : As the temperature of ice rises, the ice melts and its density? A. Decreases B. Remain constant C. Increases (Answer) D. Increases upto 10C
Last Answer : C. Increases (Answer)
Description : As the ball falls towards the ground, its velocity A. increases B. decreases C. remains constant D. becomes zero
Description : A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system (A) its internal energy (U) decreases and its entropy (S) increases (B) U and S both decreases (C) U decreases but S is constant (D) U is constant but S decreases
Last Answer : (B) U and S both decreases
Description : Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and ... increases. (A) Decreases (B) Decreases exponentially (C) Increases (D) Remain constant
Last Answer : (C) Increases
Description : For a stable phase at constant pressure and temperature, the fugacity of each component in a binary system __________ as its mole fraction increases. (A) Decreases (B) Increases (C) Remain same (D) Decreases linearly
Last Answer : (B) Increases
Description : With decrease in the grain size of a material, its creep resistance (A) Increases (B) Decreases (C) Remain constant (D) Either (A) or (B); depends on the material
Last Answer : (C) Remain constant
Description : During sensible cooling of air, its wet bulb temperature (A) Decreases but dew point remains constant (B) Increases but dew point remains constant (C) Increases & the dew point decreases (D) Decreases & the dew point increases
Last Answer : (B) Increases but dew point remains constant
Description : When a cylindrical vessel containing liquid is revolved about its vertical axis at a constant angular velocity, the pressure (A) Varies as the square of the radial distance B) Increases linearly as ... as the square of the radial distance (D) Decreases as the square of the radial distance
Last Answer : Answer: Option A
Description : As we heat a gas at constant pressure, its volume a. increases b. decreases c. stays the same d. none of the above
Description : After a projectile is fired horizontally near the earth's surface, the horizontal component of its velocity, neglecting any air resistance: w) increases steadily x) decreases steadily y) first decreases, then increases z) remains constant
Last Answer : ANSWER: Z -- REMAINS CONSTANT
Description : At boiling point of liquids, its (1) Temperature increases (2) Atmospheric pressure increases (3) Temperature remains constant (4) Vapour pressure decreases
Last Answer : Temperature remains constant
Description : When water freezes its density (1) Decreases (2) Becomes Zero (3) Remains constant (4) Increases
Last Answer : Decreases
Description : When a detergent is added to pure water, its surface tension (1) increases (2) decreases (3) remains constant (4) becomes infinite
Last Answer : decreases
Description : The degree of the B-spline with varying knot vectors a.Increases with knot vectors b.Decreases with knot vectors c.Remains constant d.none of the above
Last Answer : a.Increases with knot vectors
Description : In `beta-` decay `n//p` ratio` :` a)May inrease or decrease b) Remains constant c)Decreases d)Increases
Last Answer : In `beta-` decay `n//p` ratio` :` a)May inrease or decrease b) Remains constant c)Decreases ... B. may increase or decrease C. increases D. decreases
Description : In `alpha-` decay , `n//p` ratio `:` a)May inrease or decrease b) Remains constant c)Decreases d)Increases
Last Answer : In `alpha-` decay , `n//p` ratio `:` a)May inrease or decrease b) Remains constant c) ... off decrease B. remains constant C. decreases D. increases
Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above
Last Answer : ANSWER : B
Description : When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned
Description : Choose the correct statement. (a) Electronegativity increases down a group (b) Electronegativity decreases down a group (c) Electronegativity decreases from left to right along a period (d) Electronegativity changes along a group, but remains constant along a period
Last Answer : Ans:(b)
Description : When two gases are mixed, the entroру (a) Remains constant (b) Decreases (c) Increases (d) Becomes zero
Last Answer : Ans:(c)
Description : What happens to atmospheric pressure with increase in altitude? (1) It remains constant (2) It decreases (3) It increases (4) It constantly fluctuates
Last Answer : (2) It decreases Explanation: In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the mass of air above the measurement point. Low- ... increases, there is less overlying atmospheric mass, so that pressure decreases with increasing elevation.