Physics-DPP-1-4.First Law of Thermodynamics, Calorimetry and Heat Transfer

PHYSICS Topic: First Law of Thermodynamics, Calorimetry and Heat Transfer Date: 1. A slab consists of two parallel layers of two different materials of same thickness having thermal conductivities K1 and K2. The equivalent conductivity of the combination is: (a) K + K (b) K1 + K2 (c) 2K1K2 K1 + K2 (d) 1 2 2 K1 + K2 2K1K2 2. Steam at 1000C is passed into 1.1 kg of water contained in a calorimeter of water equivalent 0.02 kg at 150C till the temperature of calorimeter and its contents rises to 800C. The mass of the steam condensed in kilogram is : (S = 103 cal/kg- 0C and L = 540  103 cal/kg) (a) 0.130 (b) 0.065 (c) 0.260 (d) 0.135 3. If a body cools down from 800C to 600C in 10 min when the temperature of the surrounding is 300C. Then, the temperature of the body after next 10 min will be : (a) 500C (b) 480C (c) 300C (d) none of these 4. Two similar rods are joined as shown in figure. Then temperature of junction is (assume no heat loss through lateral surface of rod and temperatures at the ends are shown in steady state) (a) 500C (b) 750C (c) 66.60C (d) 33.30C 5. Equal masses of three liquids A, B, & C have temperature 100C, 250C and 400C respectively. IfAand B are mixed, the mixture has temperature of 150C. If B and C are mixed, the mixture has temperature of 300C. IfA and C are mixed, the mixture will have a temperature of : (a) 160C (b) 200C (c) 250C (d) 290C 6. The latest heat of vaporisation of water is 2240 J. If work done in the process of vaporisations of 1 gram is 168 J, then increase in internal energy will be : (a) 1904 J (b) 2072 J (c) 2240 J (d) 2408 J 7. A spherical black body with a radius of 12 cm radiates 440 W power at 500 K. If the radius were halved and the temperature doubled, the power radiated in watt would be : (a) 440 (b) 1320 (c) 880 (d) 1760 çæ 5ö÷ çæ 7ö÷ 8. One mole of monoatomic gas çγ = ÷ is mixed with 1 mole of diatomic gas çγ = ÷. What will be the value of gama for the mixture è 3ø : è 5ø (a) 1.45 (b) 1.4 (c) 1.54 (d) 1.5 9. The temperature of inside and outside of refrigerator are 273 K and 303 K respectively. Assuming that refrigerator cycle is reversible, for every Joule of work done, the heat delivered to surrounding will be : (a) 50 J (b) 30 J (c) 10 J (d) 20 J 10. Two gases A and B having same pressure P, Volume V and temperature T are mixed. If the mixture has volume and temperature as V and T respectively, then pressure of mixture will be : (a) 4 P (b) 3 P (c) 2 P (d) P PHYSICS Topic: First Law of Thermodynamics, Calorimetry and Heat Transfer Date: Answer Key 1. (b) 2. (a ) 3. (b) 4. (a) 5. (a ) 6. (b ) 7. (d ) 8. (d ) 9. ( c ) 10. ( c )

Comments

Post a Comment

Popular posts from this blog

Planning to start your own coaching institute for JEE, NEET, CBSE or Foundation? Here's why not to waste time in developing study material from scratch. Instead use the readymade study material to stay focused on quality of teaching as quality of teaching is the primary job in coaching profession while study material is secondary one. Quality of teaching determines results of your coaching that decides success & future of your coaching while good quality study material is merely a necessary teaching aid that supplements your teaching (video in Hindi)

Image
Read more

Physics-30.24-Physics-Solids and Semiconductors

UNIT 24 - SOLIDS AND SEMICONDUCTORS 1. SOLID STATE ELECTRONICS (SEMICONDUCTORS) (A) Energy bands in solids: (i) In solids, the group of closely lying energy levels is known as energy band. (ii) In solids the energy bands are analogous to energy levels in an atom. (iii) In solids the atoms are arranged very close to each other. In these atoms there are discrete energy levels of electrons. For the formation of crystal these atoms come close together, then due to nucleus-nucleus, electron-electron and electron-nucleus interactions the discrete energy levels of atom distort and consequently each energy level spits into a large number of closely lying energy levels. (iv) The number of split energy levels is proportional to the number of atoms interacting with each other. If two atoms interact then each energy level splits into two out of which one will be somewhat above and another will be somewhat below the main energy level. In solids the number of atoms is very large ( 1023). Hence eac...
Read more

Physics-31.Rotational Mechanics

5.1 DEFINITION OF CENTRE OF MASS Centre of mass: Every physical system has associated with it a certain point whose motion characterizes the motion of the whole system. When the system moves under some external forces than this point moves as if the entire mass of the system is concentrated at this point and also the external force is applied at his point of translational motion. This point is called the centre of mass of the system. Centre of mass of system of n point masses or n particles is that point about which moment of mass of the system is zero, it means that if about a particular origin the moment of mass of system of n point masses is zero, then that particular origin is the centre of mass of the system. The concept of centre of mass is a pure mathematical concept. If there are n particles having mass m1, m2 ….m n and are placed in space (x1, y1, z1), (x2, y2, z2) ……….(x n, y n, z n) then centre of mass of system is defined as (X, Y, Z) where = Y = and Z = where...
Read more