If 4.5kg of fuel completely burnt and amount of heat produced stands measured at 1,80,000 KJ. What is the calorific value?

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 get converted into heat during its fall.The value of h is [Latent heat of ice is 3.4xx10^5 J//K and g =10N//Kg ]

A person does 30 kJ work on 2 kg of water by stirring using a paddle wheel. While stirring, around 5 kcal of heat is released from water through its container to the surface and surroundings by thermal conduction and radiation. What is the change in internal energy of the system?

A sample of air weighing 1.18 g occupies 1.0 xx 10^(3) cm^(3) when kept at 300 K and 1.0 xx 10^(5) pa. When 2.0 cal of heat is added to it constant volume, its temperature increases by 1^@C . Calculate the amount if heat needed to increases the temperature of air by 1^@C at constant pressure if the mechanical equivalent of heat si 4.2 xx 10^(-1) . Assume that air behaves as an ideal gas.

A tank is filled with water to a heigth of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope t be 9.4 cm. what is the refractive index of water ? If water is replaced by a liquid of refractive index 1.63 upto the same hight, by distance would the microscope have to be moved to focus on the needle again?

A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0ms^(-1) , at right angles to the horizontal component of the earth's magnetic field, 0.30xx10^(-4)Wbm^(-2) . a. What is the instantaneous value of the emf induced in the wire? b. What is the direction of the emf? c. Which end of the wire is at the higher electrical potential?

A current of 30 A is registered when the terminals of a dry cell of EMF 1.5 VOLTS are connected through an ammeter. Neglecting the meter resistance, find the amount of heat produced in the battery in 10 seconds.