Answer any THREE question from 1 to 4.Each question carries 1 score.
1. Which of these materials will not be attracted by a magnet? (Nickel,Iron,copper,Cobalt)
2. Which of these following statements is true about mirrors? a. Radius of curvature of a spherical mirror is half of its focal length. b. Image formed by a convex mirror is always virtual c. The light rays parallel to principal axis of a convex mirror converges to its principal focus after reflection
3. Find the angle of reflection,if a ray of light is incident on a concave mirror at the pole making an angle 40ᶿ to the principal axis.
(0,30ᶿ,40ᶿ,50ᶿ)
4. Which of theᶿᶿ following is the unit of thrust? (Bar,N2,N/M2,Pascal)
Answer any FOUR questions from 5 to 9. Each question carries 2 score. (4*2=8)
5. A magnetized hacksaw blade is cut into pieces as shown in figure.
a. Find the polarity of the degree B and D b. Suggest a method to make the hacksaw blade into a permanent magnet?
6. In the figure,South poles of two bar magnets are placed facing one another.Redraw the figure and illustrate magnetic field lines?
7. Same quantity of water and kerosene are taken in two identical beakers.From the bottom of the two beakers,air bubbles are rising as shown in figure?
a. What is the reason for the growth in size of the air bubble in both beakers as it rise upwards? b. What is the reason for the large size if the air bubbles in kerosene compared to that in water?
8. Astronauts wear special clothes during space travel.Explain the reason?
9. The rays of light passing parallel to the principal axis of a spherical mirror is shown in figure?
a. Draw the reflection rays and mark principal focus of the mirror? b. Focus of the concave mirror is always real.Why?
Answer any THREE question from 10 to 13.Each question carries 3 score(3*3=6)
10. A ball rolling on a level floor gradually slows down. a. Which force causes the ball to slow down? b. Suggest two methods to reduce this force. c. What type of force is experienced here?(contact/non contact)
11. A and B are two magnetic materials.Analyse their properties and answer the questions.
- A is easily maganetised compared to B.
- Ability to retain the magnetism thus acquired is more for B than that for A a. Which of these is the most suitable material for making a permanent magnet?Explain why? b. Write the name of a substance used for making a permanent magnets?
12.Two identical bricks weighing 20N are placed in two trays filled with sand as shown in figure?
a.In which of the above situation oressure experience is more?(fig 1/fig2)why? b. What are the factors that influence pressure?
13.A magnetic needle is suspended soas to move freely in a horizontal plane. a.In which direction,north pole of the magnetic needle is ponting. b. Give reason for it? C. The case of magnetic compass is not made of soft iron.Why?
Answer any Three question from 1 to 4 (1 score each ) (3*1=3)
1.Identify the best electric conductor from the following metals. (iron ,Aluminium,Silver)
2. Which among the following is a chemical change. i)Water is becoming ice iii) Melting of wax ii)Burning of firewood iv)Water is becoming water vapour
3. Name the chemical substance added to artificial drinks for obtaining sour taste. (Tartrazane,phosphoric acid,Allyl hexanoate)
4. Find the relation and complete. Mercury cell : Watches,Calculators ………………. : Laptops,Mobile phones
Answer any four questions from 5 to 9 (2 score each) (4*2=8)
5. Classify the following mixtures into homogenous and hetrogenous.
6. The freshly cut surface of sodium metal has a shinig appearance a. Which characteristic property of metal is exhibited here? b. Sodium metal is kept in kerosene.Give reason
7.Some metals are given. [Zinc,Iron,Magnesium,Copper] a. Which one of these metals reacts vigorously with dilute hydrochloric acid? b. Which gas is evolved when metals react with dilute hydrochloric acid?
8. Some metals are given below.Pick out the statements suitable for yrues solutions.
- If an intense beam of light is passed,the path of the light becomes visible.
- Components cannot be separated by filtration using a filter paper.
- The substances settles down on standing for some time.
- If an intense beam of light is passed, the path of the light does not become visible.
9. Take some silver bromide in two dry watch glasses.Wrap one of these with a black paper and keep both of them in sunlight for some time. a. Write the observation b. Write the reason for the change.
Answer any Three question from 10 to 13 (3 Scores each) (3*3=9)
10. Give reasons for the following. i) Butter milk is not stored in Aluminium vessels. ii) Copper is used for making electric wires. iii) Iron equipments in coastal areas undergo rusting quickly.
11. Potassium permanganate is heated in a dry test tube. a) Which is the gas produced in this reaction? b) Write a test to identify this gas.write down your observation.
12. A saturated solution is prepared by dissolving salt in water,taken in a beaker. a) What do you mean by saturated solution? b) Suggest a method to dissolve more salt in the saturated solution. c) If this solution is allowed to cool slowly and carefully to room temperature,
solute does not separate out. Give the name of such solutions.