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VIBGYOR HIGH First Term Examination AY 2020-2021 SCIENCE PAPER-1 PHYSICS Grade: IX Max. Marks Date : 21/09/2020 : 80 Time Allowed: 2 hours _____________________________________________________________________ INSTRUCTIONS: The intended marks for the questions or parts of questions are given alongside the questions. Section I all questions are compulsory , Section II attempt any four questions. This paper contains 5 pages. ____________________________________________________________________ SECTION I (40 Marks) ( Attempt all questions from this section ) Q1 [10] [2] a. Define one pascal . State whether pressure is a scalar or vector quantity. b. State Archimedes principle. [2] c. Name the instrument used to control current in a circuit. Draw the circuit [2] symbol for the same. d. State Ohm s law. [2] e. A ray is incident normally on a plane mirror. [2] i. What is its angle of incidence? ii. What is the direction of reflected ray? [10] Q2 a. What is the transformation of energy that takes place when current is [2] drawn from a cell? Name a primary cell. b. Define potential difference. State its S.I unit. [2] c. Why do sea divers need special protective suit? [2] 1 d. e. i. What is anomalous expansion of water? ii. State the S.I unit of heat. [2] With the help of graph show the variation in density of water with 0 [2] 0 temperature in the range of 0 C to 10 C. [10] Q3 a. Why does a piece of ice when touched with hand, appear cool? Explain [2] b. State two factors affecting upthrust. [2] c. What do you mean by the term [2] d. i. Magnetic poles and ii. Magnetic equator Write the expression for relative density of solid and state the terms used [2] in the expression. e. [2] Icebergs are dangerous for ships. Give reason Q4 a. -3 A piece of log floats on a liquid with density 1.1gcm .What fraction of its [10] [2] volume is immersed? Given Density of log = 0.95gcm -3. b. How will you test whether a given rod is made of iron or copper? [2] c. Can two magnetic field lines intersect each other? Give reason for your [2] answer. d. Differentiate between real and virtual image. [2] e. Name two green house gases. [2] Section II (40 marks) (Attempt any four questions from this section) Q5. a. i. Calculate the potential difference across the ends of a wire of [10] [3] resistance 2 when a current 1.5A passes through it. ii. What is responsible for the flow of current through a metallic conductor? b. State any three factors affecting the resistance of a conductor. In the given circuit diagram 2 [3] c. [4] i. Name the Components A and B. ii. If a voltmeter is given, how should it be connected in the circuit to measure the potential difference? iii. How is the resistance of a wire affected if its radius is doubled? Q6 a. Derive the expression(mathematical proof) for Upthrust is equal to weight [10] [4] of displaced liquid . b. The area of cross section of press plunger of a hydraulic press is 4m 2.It is [3] required to overcome a load of 400Kgf on it. Calculate the force required on the pump plunger if the area of cross section of the plunger is 0.01m 2. c. i. A dam has broader walls at the bottom than at the top. Explain ii. State the condition for the body to sink completely in a liquid. Q7 a. i. Why is chemical reaction in secondary cell called reversible [3] [10] [3] reaction. ii. Draw the circuit symbol of galvanometer and state its purpose in the circuit. b. State three properties of magnetic field lines. [3] c. A body weighs 550gf in air and 410gf when immersed in water. Find [4] i. The volume of the body ii. The upthrust on the body iii. State the assumption made by you in part (i) iv. Express density of copper 8.83g/cm3 in kg/m3. Q8 a. With the help of a ray diagram show the image formed by an object kept [10] [3] between centre of curvature and focus of a concave mirror. State the nature of the image obtained. b. [3] Define i. Radius of curvature 3 c. ii. Centre of curvature iii. Principal axis of a spherical mirror List the characteristics of image obtained by a plane mirror. Q9 a. [10] [3] For a convex mirror, i. [4] What is the position and nature of image formed for a object kept at any place on the principal axis in front of the mirror? b. ii. Give one use of convex mirror. i. State the laws of reflection. ii. Light incident on uneven surface gives irregular reflection. [3] Will irregular reflection obey laws of reflection? c. i. What is the number of images formed when two mirrors are placed 0 [4] 0 at an angle of (a) 72 (b) 90 ii. Why is it difficult to read the image of the text formed due to reflection by a plane mirror? iii. Name the mirror which always produces an erect and virtual image. Q10 a. Derive the relationship between volume of submerged part of a floating [10] [3] body, the densities of liquid and the body. b. Pressure at free surface of a lake is P1, while at a point at depth h below [3] its surface is P2. i. How are P1 and P2 related? ii. How does the liquid pressure on a diver change if the diver moves horizontally? iii. c. Name the law on which hydraulic machine works. [4] i. What is greenhouse effect? ii. Water pipes in colder countries often burst in winter. Explain . ***** 4
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