question_answer2) The coefficients of linear expansions of brass and steel are \[{{\alpha }_{1}}\] and \[{{\alpha }_{2}}\] respectively. When we take a brass rod of length \[{{l}_{1}}\] and a steel rod of length \[{{l}_{2}}\] at \[{{0}^{o}}C,\] then the difference in their lengths \[({{l}_{2}}-{{l}_{1}})\] will remain the same at all temperatures if: [AIPMT 1999]
question_answer3) Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine? [AIPMPT (S) 2008] \[(g=10\,\,m/{{s}^{2}})\]
question_answer4) On a new scale of temperature (which is linear) and called the W scale, the freezing and boiling points of water are \[39{}^\circ W\] and respectively. What will be the temperature on the new scale, corresponding to a temperature of \[39{}^\circ W\] on the Celsius scale? [AIPMPT (S) 2008]
question_answer5) An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature\[20\,{}^\circ C\]? The temperature of boiling water is \[100\,{}^\circ C\]. [AIPMPT (S) 2008]
question_answer6) When 1 kg of ice at \[0{{\,}^{o}}C\] melts to water at \[0{{\,}^{o}}C,\] the resulting change in its entropy, taking latent heat of ice to be \[80\text{ }cal/{}^\circ C,\] is [AIPMT (S) 2011]
question_answer7) Steam at \[100{}^\circ C\] is passed into 20 g of water at\[10{}^\circ C\]. When water acquires a temperature of \[80{}^\circ C,\] the mass of water present will be [Take specific heat of water \[=1\,\,cal\,\,{{g}^{-1}}{{\,}^{o}}{{C}^{-1}}\] and latent heat of steam \[=540\,\,cal\,\,{{g}^{-1}}\]] [NEET 2014]
question_answer8) 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 rise of \[40\,{}^\circ C\] in its temperature is [NEET (Re) 2015]
question_answer9) Coefficient of linear expansion of brass and steel rods are \[{{\alpha }_{1}}\] and \[{{\alpha }_{2}}\]. Lengths of brass and steel rods are \[{{\ell }_{1}}\] and \[{{\ell }_{.2}}\] respectively. If \[({{\ell }_{2}}-{{\ell }_{1}})\] is maintained same at all temperatures, which one of the following relations holds good? [NEET - 2016]
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 gets converted into heat during its fall. The value of h is : [NEET - 2016]
[Latent heat of ice is \[3.4\text{ }\times \text{ }{{10}^{5}}\text{ }J/kg\] anz\[g=10\text{ }N/kg\]]
A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is- [NEET 2019]
question_answer12) The quantities of heat required to raise the temperature of two solid copper spheres of radii \[{{r}_{1}}\] and \[{{r}_{2}}\text{ (}{{r}_{1}}=1.5\text{ }{{r}_{2}})\] through 1 K are in the ratio: [NEET 2020]