Description : A copper disc has a hole. If the disc is heated, the size of the hole - (1) increases (2) decreases (3) No change (4) first increases and than decreases
Last Answer : (1) increases Explanation: When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter (sum of two radii) of the circular hole also increases.
Description : If there is a circular hole in a metal plate, what happens to the radius of the hole when the plate is heated? (1) Increases (2) Decreases (3) Unchanged (4) Depends upon the metal
Last Answer : (1) Increases Explanation: When a metal plate with a circular hole at its centre is heated, definitely along with the areal expansion of the plate the diameter of the circular hole also increases. Using ... of expansions, we find that the hole radius increases at the same linear rate as the metal.
Last Answer : Increases
Description : A copper plate has a circular hole cut in it. If the plate is heated to a higher temperature, the diameter of the hole (a) Becomes smaller (b) Increases (c) Remains constant (d) Increases but the total area of the plate remains constant
Last Answer : Ans:(b)
Description : When water is heated from 0°C to 10°C. Its volume (1) increases (2) decreases (3) does not change (4) first decreases and then increases
Last Answer : (4) first decreases and then increases
Description : The density of the liquid when heated (1) decreases (2) increases (3) does not change (4) may increase of decrease depending on pressure
Last Answer : (1) decreases Explanation: The mass density of a material varies with temperature and pressure. Increasing the temperature of a substance (with some exceptions) decreases its density by increasing the volume of ... bottom to top of the fluid due to the decrease of the density of the heated fluid.
Last Answer : decreases
Description : If a metallic object is heated, its density generally: w) increases x) decreases y) fluctuates randomly z) remains the same
Last Answer : ANSWER: X -- DECREASES
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole? (1) Increase (2) Decrease (3) Remain constant (4) Will increase first and then decrease
Last Answer : (1) Increase Explanation: Assuming the disc is uniform and isotropic (the same in different directions), the hole will expand in the same ratio as the metal. It is because the thermal expansion equation ... is made out of metal. And if the circumference of the hole expands, so does the diameter.
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole ? (1) Increase (2) Dacrease (3) Remain constant (4) Will increase first and then dcrease
Last Answer : Increase
Description : When a ring of metal is heated what happens to its hole? (1) expands (2) contracts (3) it expands or contracts according to its diameter (4) it expands or contracts according to its coefficient of expansion
Last Answer : (1) expands Explanation: The hole size will increase because in expansion the size between two molecules, do not increase so when the molecules on the outer edge move outward. Due to expansion, the ... expansion is the tendency of matter to change in volume in response to a change in temperature.
Description : When a ring of metal is heated what happens to its hole ? (1) expands (2) contracts (3) it expands or contracts according to its diameter (4) it expands or contracts according to its coefficient of expansion
Last Answer : expands
Description : Air at a particular humidity is heated in a furnace. The new dew point (A) Decreases (B) Increases (C) Depends on the extent of heating (D) Remain unchanged
Last Answer : (B) Increases
Description : When an unsaturated air-water mixture is heated at constant pressure, then (A) The partial pressure of water vapour increases (B) The specific humidity decreases (C) The relative humidity increases (D) The relative humidity decreases
Last Answer : D) The relative humidity decreases
Description : A metal sheet with circular hole is heated. what change will be in the hole?
Last Answer : It will Expand
Description : 1. Which post does the Constitution of India does not mention? 2. What is the Solar Corona' mainly? 3. Who was a blind poet who worshipped Krishna and spread Krishna Bhakti cult? 4. A ... ? 20. By inserting a soft iron piece into solenoid, what does the strength of the magnetic field?
Last Answer : Answer : 1. The Deputy Prime Minister 2. Consists of molten lava 3. Surdas 4. It will Expand 5. The Bank Note Press, Dewas 6. Kathak 7. Hydrogen 8. Alain khan, the father of Dilawar Khan 9. ... Sarwani 14. 1991 15. 15 16. 46 gram 17. Chinook 18. Painters 19. State Election Commission 20. Increase
Description : The surface tension of water on adding detergent to it – (1) increases (2) decreases (3) no change (4) becomes zero
Last Answer : (2) decreases Explanation: In the solid and liquid phase, water molecules are bonded to each other by virtue of an interaction between hydrogen atoms on one molecule and the oxygen atom of another - the process ... to as "hydrogen bonding." The result is a kind of "skin" on liquid water's surface.
Description : The surface tension of water on adding detergent to it (1) increases (2) decreases (3) no change (4) becomes zero
Description : If ice floating on water in a vessel melts, the water level in the vessel - (1) increases (2) does not change (3) first increases before decreasing (4) decreases
Last Answer : (2) does not change Explanation: When ice floating on water in a vessel melts, the water level in the vessel does not change. This is because when floating, the ice displaces an amount of water ... that the mass of the liquid displaced by a floating object is equivalent to the mass of the object.
Description : If ice floating on water in a vessel melts, the water level in the vessel _______. (1) increases (2) does not change (3) first increases before decreasing (4) decreases
Last Answer : (2) does not change Explanation: When ice floating on water in a vessel melts, the water level in the vessel does not change. This is because when floating, the ice displaces an amount of water equal to its mass, and when melted, it becomes an amount of water equal to its mass.
Last Answer : does not change
Description : Which of the following is the best example of law of conservation of mass? [NCERT 1975] (A) 12 g of carbon combines with 32 g of oxygen to form 44 g of CO2. (B) When 12 g of carbon is ... mass remains unaltered. (D) The weight of a piece of platinum is the same before and after heating in air.
Last Answer : (A) 12 g of carbon combines with 32 g of oxygen to form 44 g of CO2.
Description : When pressure is increased the melting point of ice – (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice
Last Answer : (3) decreases Explanation: In this case. if we increase the pressure on the ice the ice-water system wants to try to lower it again. It can do that by making itself fit into a ... the melting point of ice decreases because of the inversal relationship between the pressure and melting point of ice.
Description : When a person sitting on a swing stands up on the swing, the frequency of oscillation – (1) decreases (2) increases (3) becomes infinite (4) does not change
Last Answer : (2) increases Explanation: In Simple Harmonic Motion, the frequency of the oscillation (1) is the number of oscillations per second which is expressed as f = 1/T where T is the time period (the time for the oscillator to complete one cycle).
Description : When a person sitting on a swing stands up on the swing, the frequency of oscillation (1) decreases (2) increases (3) becomes infinite (4) does not change
Last Answer : increases
Description : When pressure is increased the melting point of ice (1) increases (2) does not change (3) decreases (4) depends on the impurities in the ice
Description : On heating a circular metallic disc with a circular hole at the centre, the diameter of the hole will (a) decrease (b) remain the same (c) increase (d) first increase, then decrease
Last Answer : Ans:(c)
Description : Resistance of a copper wire decreases when ......................increases
Last Answer : Resistance of a copper wire decreases when diameter increases
Description : Copper sulphate crystals when heated strongly, lose their water of crystallization to give anhydrous copper sulphate accompanied by a change in color from: (a). Blue to green (b). Blue to white (c). Blue to sky blue (d). Blue to grey
Last Answer : (b). Blue to white
Description : What will happen if a sheet of metal with a hole in it is heated?
Last Answer : Need answer
Description : A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole?
Last Answer : Decrease
Description : For which of the following substances, the resistance decreases with increase in temperature? (1) Pure silicon (2) Copper (3) Nichrome (4) Platinum
Last Answer : (3) Nichrome Explanation: Nichrome has high resistance and it is called a resistor.
Last Answer : Nichrome
Description : Why does bleeding occur through the nose in high mountainous regions? (1) The pressure of blood in capillaries is greater than the outside pressure (2) The pressure at high altitudes is ... of a person increases at high altitudes (4) The blood pressure fluctuates and finally decreases drastically
Last Answer : (3) The blood pressure of a person increases at high altitudes Explanation: Nose bleeds can occur at high altitudes. The bleeding may be caused by the change in air pressure associated with the ... of blood from the nostrils. Stress and anxiety raises the blood pressure, complicating the nose bleed.
Description : Why does bleeding occur through the nose in high mountainous regions ? (1) The pressure of blood in capillaries is greater than the outside pressure (2) The pressure at high altitudes is ... of a person increases at high altitudes (4) The blood pressure fluctuates and finally decreases drastically
Last Answer : The blood pressure of a person increases at high altitudes
Description : In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The capillary rise of water (A) Depends upon the force responsible (B) Increases as the size of the soil particles increases (C) Decreases as the size of the soil particles decreases (D) Is less in wet soil than in dry soil
Last Answer : (A) Depends upon the force responsible
Description : In a heat exchanger with steam outside the tubes, a liquid gets heated to 45°C, when its flow velocity in the tubes is 2 m/s. If the flow velocity is reduced to 1 m/s, other things remaining ... than 45°C (B) More than 45°C (C) Equal to 45°C (D) Initially decreases and remains constant thereafter
Last Answer : (B) More than 45°C
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 : Feeding of milk cattle with cotton seeds (a) Increases fat content temporarily (b) Decreases fat content temporarily (c) May decrease or increase fat content (d) Causes no change in fat content
Last Answer : Ans:(a)
Description : Air resistance ______ with an increase in the speed of the object moving through it. a) increases b)decreases c)remains same d)no change
Last Answer : a) increases
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 : Melting point of ice _______. (1) increases with increase of pressure (2) decreases with increase of pressure (3) is independent of pressure (4) None of these
Last Answer : (2) decreases with increase of pressure Explanation: The melting point of ice at 1 atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K); this is also known as the ice point.
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 : Energy in reflected light : (1) does not depends on the angle of incidence (2) increases with the increase in angle (3) decreases with the increase in angle of incidence (4) becomes maximum for angle of incidence equal to 45°
Last Answer : (2) increases with the increase in angle Explanation: Reflected waves are simply those waves that are neither transmitted nor absorbed, but are reflected from the surface of the medium they encounter. The ... depends on the nature of the surface and the angle at which the wave strikes the surface.
Description : The velocity of sound in air – (1) decreases with increase of temperature (2) increases with decrease of temperature (3) does not depend on temperature (4) decreases with decrease of temperature
Last Answer : (4) decreases with decrease of temperature Explanation: Assuming air to be an ideal gas, the speed of sound c depends on temperature only, not on the pressure or density. As air ... to the individual air particles having extra kinetic energy at higher temperatures and lesser at lower temperatures.
Description : Negative feedback in amplifiers – (1) increases bandwidth and decreases noise (2) decreases bandwidth and decreases noise (3) increases bandwidth and in-creases noise (4) decreases bandwidth and increases noise
Last Answer : (1) increases bandwidth and decreases noise Explanation: Voltage gain, input impedance, output impedance, bandwidth etc. are few important characteristics of an amplifier. These parameters are more or ... be controlled. This can be conveniently achieved by employing a technique, called the feedback.
Description : The wavelength at which the peak of intensity of blackbody radiation Occurs – (1) increases with increase in temperature (2) decreases with increase in temperature (3) is the same at all temperatures (4) does not follow any pattern as temperature changes
Last Answer : (2) decreases with increase in temperature Explanation: According to Wien's displacement law, when the temperature of a blackbody radiator increases, the overall radiated energy increases. ... to its temperature. Shorter-wavelength (higher-frequency) light corresponds to higherenergy photons.
Description : Vegetables are cooked in lesser time by adding a pinch of salt while cooking because (1) boiling point of water increases (2) latent heat of vaporization of water decreases (3) latent heat of vaporization of water increases (4) boiling point of water decreases
Last Answer : (1) boiling point of water increases Explanation: Adding salt raises the boiling point of water, which allows food to cook at higher temperature. The higher the temperature, the higher the rate of heat transfer between the food and water, thus it cooks more quickly.
Description : According to special theory of relativity the mass of a particle – (1) increases with increase in velocity with respect to an observer. (2) decreases with increase in velocity. (3) decreases with decrease in velocity. (4) is independent of its velocity.
Last Answer : (1) increases with increase in velocity with respect to an observer. Explanation: According to the Special Theory of Relativity, the mass of a moving object measures more as its velocity increases until, ... becomes infinite. This is because as an object gains speed, it gains more (kinetic) energy.