Formatting page ...
The Assembly of God Church School 125/1 Park Street, Kolkata-700017 Pre - Board Examination-2017-2018 _____________________________________________________________________________ PHYSICS SCIENCE Paper 1 (Two hours) Answers to this Paper must be written on the paper provided separately. You will not be allowed to write during the first 15 minutes. This time is to be spent in reading the Question Paper. The time given at the head of this Paper is the time allowed for writing the answers. _____________________________________________________________________________ _ Section I is compulsory. Attempt any four questions from Section II. The intended marks for questions or parts of questions are given in brackets [ ]. _____________________________________________________________________________ _ SECTION I (40 Marks) Attempt all questions from this Section. Question 1 a) Can the heat capacity of a substance be infinite? Justify your answer. [2] b) i) What is indicated by the ratio of change of current to change of voltage of V-I graph? ii) The slope of V-I graph of an ohmic conductor makes an angle 30 to the current axis. What is the resistance of the conductor? [2] c) i)What is measured by the unit Sievert (Sv)? ii) Give one example of internal source of background radiation. [2] d) A convex lens of focal length 15 cm is placed on a horizontal mirror. A pin is placed above the lens such that there is no parallax between the pin and its image. Draw a neat diagram to show this effect. What is indicated by the height of the pin from the lens? [2] e) When a body moves in a circular path how much work is done? Give reason. [2] Question 2 a) Momentum of a particle of mass 2 kg is 10 Ns. What is the speed and energy of the particle? [2] b) Does the boiling point of water change with altitude? If so, how? [2] c) Is it possible to burn a piece of paper using a convex lens in day-light without using matches or any direct flame? Draw a diagram to support your answer. [2] d) In case of single movable pulley show that t is gained in force is lost in speed . [2] e) A uniform metal wire has resistance of 80 . It is cut into four equal lengths. Find the equivalent resistance when three parts are connected in parallel and fourth part is in parallel with them. [2] Question 3 a) What is electron volt? Find out the ratio of kW and MeV? [2] b) Some portion of a filament of a room heater is removed and re-joined. It is connected to same power supply. Whether the bulb will glow brighter or dimmer? Explain [2] c) State the energy changes which take place the following: i) Photosynthesis in green leaves. ii) charging a battery. [2] d) A circular coil carries current in clockwise direction. What magnetic pole induces at its centre? Show two magnetic lines of force around the coil. [2] e) State any two difference between musical sound and noise. [2] 1|Page This paper consists of 4 printed pages.
|
