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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
Triple point of water isA. `273.16^(@) F`B. `273.16 K`C. `273.16^(@)C`D. `273.16 R` |
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Answer» Correct Answer - B |
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| 102. |
A system is provided with 200 cal of heat and the work done by the system on the surrounding is `40J`. Then its internal energyA. 840 dyneB. 840 WC. 840 ergD. 840 J |
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Answer» Correct Answer - D |
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| 103. |
Air fills a rooms in winter at `7^@ C` and in summer st `37^@ C`. If the pressure is the same in winter and summer, the ratio of the weight of the air filled in winter and that in summer is.A. `2.2`B. `1.75`C. `1.1`D. `3.3` |
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Answer» Correct Answer - C ` n = (p V)/(R T)` `:. n prop 1/ T or m prop 1/T` `(m_1)/(m_2) = (T_2)/(T_1) = (273 +37)/(273 + 7)` = `(310)/(280) = 1.1`. |
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| 104. |
An insulated box containing a monoatomic gas of molar mass (M) moving with a speed `v_0` is suddenly stopped. Find the increment is gas temperature as a result of stopping the box. |
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Answer» Correct Answer - A Decrease in kinetic energy = increase in internal energy of the gas `:. 1/2 m v_0^2 = (n f)/2 R Delta T = (m/M)(3/2 R)Delta T` `:. Delta T = (M v_0^2)/(3 R)`. |
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| 105. |
Temperature of two moles of a monoatomic gas is increased by `300 K` in the process `p prop V`. Find (a) molar heat capacity of the gas in the given process (b) heat required in the given process. |
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Answer» Correct Answer - A::B::C (a) Molar heat capacity `C` is given by `C = C_V + R/ (1 - x)` in the process `p V^(x) =` constant . Now, `C_V = 3/2 R` for monoatomic gas. Further, the given process can be written as `PV^-1 = constant` `:. x = -1` Substituting the values in Eq. (i), we have `C = 3/2 R + R(1 + 1) = 2 R` (b) `Q or DeltaQ = n C Delta T` Substituting the values, we have `Delta Q = (2) (2R) (300)` = `1200 R`. |
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| 106. |
Hailstone at `0^@C` from a height of 1 km on an insulating surface converting whole of its kinetic energy into heat. What part of it will melt? (`g=10 m//s`)A. `(1)/(33)`B. `(1)/(8)`C. `(1)/(33)xx10^(-4)`D. All of it will melt |
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Answer» Correct Answer - A |
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| 107. |
A bullet moving with a uniform velocity v, stops suddenly after hitting the target and the whole mass melts be m, specific heat S, initial temperature `25^(@)C,` melting point `475^(@)C` and the latent heat L. Then v is given byA. `mL=mS(475-25)+(1)/(2).(mv^(2))/(J)`B. `mS(475-25)+mL=(mv^(2))/(2J)`C. `mS(475-25)+mL=(mv^(2))/(J)`D. `mS(475-25)-mL=(mv^(2))/(2J)` |
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Answer» Correct Answer - B |
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| 108. |
In a water-fall the water falls from a height of 100 m . If the entire K.E. of water is converted into heat, the rise in temperature of water will beA. `0.23^(@)C`B. `0.46^(@)C`C. `2.3^(@)C`D. `0.023^(@)C` |
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Answer» Correct Answer - A |
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| 109. |
A stationary object at `4^(@)C` and weighing `3.5 kg` falls from a height of `2000 m` on a snow mountain at `0^(@)C.` If the temperature of the object just before hitting the snow is `0^(@)C `and the object comes to rest immediately? (g=10m//s^(2))` and heat of ice `=3.5xx10^(5) joule //sec), then the object will meltA. 2 kg of iceB. 200 gm of iceC. 20 gm iceD. 2 gm of ice |
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Answer» Correct Answer - B |
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| 110. |
In a water-fall the water falls from a height of 100 m . If the entire K.E. of water is converted into heat, the rise in temperature of water will beA. 350 calB. 150 calC. 60 calD. 6 cal |
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Answer» Correct Answer - A |
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| 111. |
A steel ball of mass 0.1 kg falls freely from a height of 10 m and bounces to a height of 5.4 m from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is (specific heat of steel `=460 K//kg^(@)//C,g=10 m//s^(2)`)A. `0.01^(@)C`B. `0.1^(@)C`C. `1^(@)C`D. `1.1^(@)C` |
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Answer» Correct Answer - b |
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| 112. |
Statement-1: Fahrenheit is the smallest unit measuring temperature Statement-2: Fahrenheit was the first temperature scale used for measuring temperatureA. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is falseD. If the assertion and reason both are false |
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Answer» Correct Answer - C |
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| 113. |
A steel scale measures the length of a copper wire as `80.0 cm` when both area at `20^(@)C` (the calibration temperature for scale). What would be the scale read for the length of the wire when both are at `40^(@)C`? (Given `alpha_("steel") = 11 xx 10^(-6) per ^(@)C` and `alpha_("copper") = 17 xx 10^(-6) per^(@)C`)A. `80.0096cm`B. `80.0272cm`C. 1cmD. `25.2cm` |
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Answer» Correct Answer - A |
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| 114. |
A steel meter scale is to be ruled so that millimeter intervals are accurate within about `5xx10^(-5)` mm at a certain temperature. The maximum temperature variation allowable during the ruling is (Coefficient of linear expansion of steel `=10xx10^(-6)K^(-1)`)A. `2^(@)C`B. `5^(@)C`C. `7^(@)C`D. `10^(@)C` |
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Answer» Correct Answer - b |
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| 115. |
On centigrade scale the temperature of a body increases by 30 degrees. The increase in temperature on Fahrenheit scale isA. `50^(@)`B. `40^(@)`C. `30^(@)`D. `54^(@)` |
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Answer» Correct Answer - D |
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| 116. |
The correct value of `0^(@)C` on the Kelvin scale isA. `273.15 K`B. `273.00 K`C. `273.05 K`D. `273.63 K` |
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Answer» Correct Answer - A |
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| 117. |
If mass-energy equivalence is taken into account, when water is cooled to from ice, the mass of water shouldA. IncreaseB. Remain unchangedC. DecreaseD. First increase then decrease |
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Answer» Correct Answer - B |
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| 118. |
The figure shows a glass tube (linear co-efficient of expansion is `alpha`) completely filled with a liquid of volume expansion co-efficient `gamma` . On heating length of the liquid column does not change. Choose the correct relation between `gamma` and `alpha` A. `gamma = alpha`B. `gamma = 2alpha`C. `gamma = 3 alpha`D. `gamma = (alpha)/(3)` |
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Answer» Correct Answer - b |
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| 119. |
Assertion : A beaker is completely filled with water at `4^(@)C` . It will overflow, both when heated or cooled. Reason : There is expansion of water below and above `4^(@)C` .A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is falseD. If the assertion and reason both are false |
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Answer» Correct Answer - A |
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| 120. |
What happens when pressure is raised on the surface of water ?(A) Boiling point increases and melting point decreases (B) Boiling point decrease and melting point increases. (C) Both boiling point as well as melting point increase. (D) both boiling point as well as melting point increase. |
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Answer» Answer is (A) Boiling point increases and melting point decreases |
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| 121. |
Two blocks of ice when pressed together join to form one block. This happens because : (A) melting point rises with pressure. (B) melting point falls with pressure. (C) heat is absorbed from outside. (D) heat is rejected to outside. |
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Answer» Answer is (B) melting point falls with pressure. Melting point falls due o pressure, So the ice at the joint melts. when pressure to removed. It again freezes and one block is formed. |
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| 122. |
The average kinetic energy of the molecules of an ideal gas at `10 ^@ C` has the value (E). The temperature at which the kinetic energy of the same gas becomes (2 E) is.A. `5^@ C`B. `10^@ C`C. `40^@ C`D. None of these |
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Answer» Correct Answer - D `E prop T` `:. (T_2)/(T_1) = (E_2)/(E_1) = (2 E)/E = 2` `:. T_2 = 2 T_1 = 2(273 + 10) ` = `566 K = 293^@ C`. |
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| 123. |
At `0^@ C and 1.0 atm ( = 1.01 xx 10^5 N//m^2)` pressure the densities of air, oxygen and nitrogen are `1.284 kg//m^3, 1.429 kg//m^3 and 1.251 kg //m^3` respectively. Calculate the percentage of nitrogen in the air from these data, assuming only these two gases to be present. |
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Answer» Correct Answer - A::B Let mass of nitrogen `= (m) g`. Then, mass of oxygen `= (100 - m) g` Number of moles of nitrogen, `n_1 = (m)/(28)` and number of moles of oxygen `n_2 = ((100 - m)/(32))` For air `rho = (p M)/(R T) = (p)/(R T)((m_1 +m_2)/(n_1 + n_2))` `:. 1.284 = (1.01 xx 10^5)/(8.31 xx 273)[(100 xx 10^-3)/((m//28) +(100 -m)//32)]` Solving this equation, we get `m = 76.5 g` This is also percentage of `N_(2)` by mass on air as total mass have taken is `100 g`. |
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| 124. |
In case of hydrogen and oxygen at (NTP), which of the following is the same for both ?A. Average linear momentum per molecule.B. Average (KE) per molecule.C. (KE) per unit volumeD. (KE) per unit mass |
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Answer» Correct Answer - B Hydrogen and oxygen both are diatomic gases. Therefore, average kinetic energy per molecule is `f/2 k T` or 5/2 k T` (as f = 5) |
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| 125. |
The volume of a diatomic gas `(gamma = 7//5)` is increased two times in a polytropic process with molar heat capacity ` C = R`. How many times will the rate of collision of molecules against the wall of the vessel be reduced as a result of this process? |
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Answer» Correct Answer - B::C::D In the process `p V^x = constant C = (R )/(gamma - 1) + (R )/(1 - x)`, Given, `C = R and gamma = 7//5` Substituting these values, we get `x = (5)/(3)` Now, `PV^(5//3) = "constant or" p prop (1)/((V)^(5//3))` By increasing volume to two times pressure will decrease `(2)6(5//3)` times. `v_(r m s) prop sqrt(T) "or "v_(r m s) prop sqrt(p V)` or `v_(r m s) "will become" sqrt((2))/(2)^(5//3)` times or `v_(r m s) "will become" (2)^(-1//3)` times or `(1)/((2)^(1//3)` times Now, `p prop ("no. of collisions") (v_(r m s)` `(1)/((2)^(5//3) prop ("no. of collisions") (1)/((2)^(1//3)` or number of collisions will decrease `(2)^(4//3)` times. |
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| 126. |
An ideal gas is taken through a process in which the pressure and the volume are changed according to the equation `p=kv`. Show that the molar heat capacity of the gas for the process is given by `(C=C_v + ( R)/(2))`. |
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Answer» Correct Answer - A `pV^-1 = constant` `:. C = C_V + R/(1 - x)` Here `x = -1` `C - C_V + R/2`. |
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| 127. |
A piece of metal weighs 46 g in air and 30 g in lipuid of density `1.24 xx 10^3 kg m^(-3)` kept at `27^0C`. When the temperature of the liquid is raised to `42^0C` the metal piece weights 30.5 g . The density of the liqued at `42^0 C` is `1.20 xx 10^3 kg m^(-3)`. Calculate the coefficient of linear expandsion of the metal.A. `3.316xx10^(-5)//^(@)C`B. `2.316xx10^(-5)//^(@)C`C. `4.316xx10^(-5)//^(@)C`D. None of these |
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Answer» Correct Answer - B |
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| 128. |
(a) What is the average translational kinetic energy of a molecule of an ideal gas at temperature of `[email protected] C` ? (a) What is the total random translational kinetic energy of the molecules in one mole of this gas ? ( c) What is the rms speed of oxygen molecules at this temperature ? |
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Answer» Correct Answer - A::B::C::D (a) `k_T = 3/2 k T` = `3/2 (1.38 xx 10^-23) (300)` = `6.21 xx 10^-21 J` (b) `k_T` in one mole `= 3/2 R T` `= 3/2 xx 8.31 xx 300` = `3740 J` ( c) `V_(r m s)= sqrt ((3 R T)/(M)) = sqrt((3xx 8.31 xx 300)/(32 xx 10^-3))` `= 484 m//s`. |
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| 129. |
A bottle of water at 0° C is opened on the surface of moon. This of the following correctly expresses the behaviour of water in it. (A) it will freeze. (B) it will decompose into H2 and O2. (C) It will boil. (D) none of the above. |
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Answer» Answer is (C) It will boil. The atmospheric pressure on the moon is very small. Due to this water in bottle will start boiling as soon as lid is opened. It is because a liquid starts boiling when its vapour pressure becomes equal to atmospheric pressure. |
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| 130. |
A liquid boils at a temperature. At which the pressure of air on its surface is : (A) equal to vapour pressure. (B) less than the vapour pressure. (C) more than the atmosphere. (D) equal to 760 mm of HG. |
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Answer» Answer is (A) equal to vapour pressure. |
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| 131. |
An equilateral triangle `ABC` is formed by joining three rods of equal length and `D` is the mid-point of `AB`. The coefficient of linear expansion for `AB` is `alpha_(1)` and for `AC` and `BC` is `alpha_(2)`. The relation between `alpha_(1)` and `alpha_(2)`, if distance `DC` remains constant for small changes in temperature is A. `alpha_(2)=3alpha_(1)`B. `alpha_(2)=4alpha_(1)`C. `alpha_(1)=3alpha_(2)`D. `alpha_(1)=4alpha_(2)` |
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Answer» Correct Answer - D |
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| 132. |
A device used to measure very high temperature isA. PyrometerB. ThermometerC. BolometerD. Calorimeter |
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Answer» Correct Answer - A |
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| 133. |
A pendulum clock keeps correct time at `0^(@)C`. Its mean coefficient of linear expansions is `alpha//.^(@)C`, then the loss in seconds per day by the clock if the temperature rises by `t^(@)C` isA. `((1)/(2)alpha txx864000)/(1-(alpha t)/(2))`B. `(1)/(2)alpha txx86400`C. `((1)/(2)alpha t xx86400)/((1-(alpha t)/(2))^(2))`D. `((1)/(2)alpha t xx86400)/(1+(alpha t)/(2))` |
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Answer» Correct Answer - B |
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| 134. |
A student takes 50 g wax (specific heat `=0.6 kcal//kg^(@)C`) and heats it till it boils. The graph between temperature and time is as follows. Heat supplied to the wax per minute and boiling point are respectively.A. `500 cal, 50^(@)C`B. `1000 cal, 100^(@)C`C. `1500 cal, 200^(@)C`D. `200^(@)C` |
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Answer» Correct Answer - C |
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| 135. |
An iron tyre is to be fitted onto a wooden wheel 1.0 m in diameter. The diameter of the tyre is 6 mm smaller than that of wheel the tyre should be heated so that its temperature increases by a minimum of (coefficient of volume expansion of iron is `3.6xx10^-5//^@C`)A. `167^(@)C`B. `334^(@)C`C. `500^(@)C`D. `1000^(@)C` |
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Answer» Correct Answer - C |
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| 136. |
Heat is supplied to a certain homogeneous sample of matter, at a uniform rate. Its temperature is plotted against time, as shown Which of the following conclusions can be drawn? (i) Its specific heat capacity is greater in the solid state than the liquid state. (ii) Its specific heat capacity is greater in the liquid state than in the solid state. (iii) Its latent heat of vaporization is greater than its latent heat of fusion. (iv) Its latent heat of vaporization is smaller than its latent heat of fusionA. Its specific heat capacity is greater in the solid state than in the liquid stateB. Its specific heat capacity is greater in the liquid state than in the solid stateC. Its latent heat of vaporization is greater than its latent heat of fusionD. Its latent heat of vaporization is smaller than its latent of fusion |
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Answer» Correct Answer - B::C |
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| 137. |
A bimetallic strip is formed out of two identical strips one of copper and the other of brass. The co-efficients of linear expansion of the two metals are `alpha_(C)` and `alpha_(B)`. On heating, the the strip bends to form an are of radius of curvature `R`. Then `R` isA. Proportional to `Delta T`B. Inversely proportional to `Delta T`C. Proportional to `|alpha_(B)-alpha_(C )|`D. Inversely proportional to `|alpha_(B)-alpha_(C )|` |
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Answer» Correct Answer - B::D |
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| 138. |
Steam at `100^@C` is passed into 1.1 kg of water contained in a calorimeter of water equivalent 0.02 kg at `15^@C`till the temperature of the calorimeter and its contents rises to `80^@C` . The mass of the steam condensed in kilogram isA. `0.130`B. `0.065`C. `0.260`D. `0.135` |
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Answer» Correct Answer - A |
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| 139. |
If on heating liquid through `80^(@)C`, the mass expelled is `(1//100)^(th)` of mass still remaining, the coefficient of apparent expansion of liquid isA. `1.25xx10^(-4)//^(@)C`B. `12.5xx10^(-4)//^(@)C`C. `1.25xx10^(-5)//^(@)C`D. None of these |
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Answer» Correct Answer - A |
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| 140. |
A thin cylindrical metal rod is bent into a ring with a small gap as shown in figure. On heating the systemA. x decreases, r and d increase dB. x and r increase, d dencreasesC. x, r and d all increaseD. Data insufficient to arrive at a conclusion |
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Answer» Correct Answer - C |
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