Available Answers

1. 1.

   Fill in the blanks:

   1. Evaporation has a ____________ effect.
   2. Molecules of a substance are always in a state of ____________.
   3. The boiling point of water is ____________.
   4. The opposite phenomenon of sublimation is ____________.
   5. Gases have the ____________ intermolecular space among its molecules.
   6. A substance with relative density ____________  than 1 implies that it is heavier than water.
   7. The S.l. unit of density is ____________.
   8. Mass = Density x ____________.
   9. The density of a body floating on water is ____________  than 1000 kg m^-3.
   10. 1kg is the mass of ____________ mL of water at 4°C.
   11. For a given depth, a liquid exerts ____________ pressure in all the directions.
   12. The pressure exerted by a liquid is ____________ of the size and shape of the container.
   13. At high altitudes, the atmospheric pressure is ____________.
   14. The caterpillar track ____________ the surface area that reduces the pressure on the ground.
   15. The pressure is ____________ proportional to the area.
   16. The more the energy content in a body, ____________ is the capacity to do work.
   17. Work is zero if the motion of the body is ____________ to the force.
   18. Displacement has both ____________ and direction.
   19. When the bob of a pendulum reaches the mean position, the potential energy becomes ____________.
   20. When the roller coaster car is present at the top of the coaster, it possesses the ____________ amount of potential energy.
   21. ____________ is the angle between any two refracting surfaces of prism.
   22. The perpendicular distance between the incident ray and the emergent ray is called ____________.
   23. In case of convex mirror, the image formed is always ____________, ____________ and diminished for every position of the object.
   24. When the ray of light travels from a rarer to a denser medium, the angle of incidence is ____________ than the angle of refraction.
   25. ____________ is the most beautiful demonstration of dispersion of white light in nature.
   26. The gap between the cement roads is helpful in allowing ____________ of the concrete.
   27. In order to seal the metallic wire into the glass, ____________ wires are used.
   28. On boiling 1 litre of water at the room temperature, the volume is seen to be increased by ____________.
   29. Iron expands ____________ than copper.
   30. A longer rod expands ____________ on heating than a smaller rod when heated at the same temperature.
   31. A higher ____________ would result in louder sound.
   32. A woman's voice is ___________ than a mans voice.
   33. Sound cannot travel in ____________.
   34. The lowest frequency of the note is called the ____________.
   35. The pitch is determined by the ____________ of vibrations of a sound wave.
   36. ____________ takes place where the circuit draws a large amount of current from the mains, causing heating of the connecting wires and circuit.
   37. The fuse is always placed in the ____________ wire at the entry point of the current
   38. The uncharged body is charged by bringing it in contact with the charged body in  ____________.
   39. The two most widely used electroscopes are ____________ and gold-leaf electroscope.
   40. Like charges ____________ each other and unlike charges ____________ each other.
2. 2.

   State whether the given statements are true (T) or false (F):

   1. When heat is supplied to matter the energy of its molecules increases and they start vibrating vigorously
   2. During the process of evaporation, the liquids releases heat from the body.
   3. The liquids are not too rigid but can be beaten into thin sheets.
   4. Gases neither have a fixed shape nor a fixed volume.
   5. The solids can be compressed to a large extent, expand a lot on heating.
   6. The SI unit of relative density is g cm^-3.
   7. The relative density of water is 4.0.
   8. Density bottle can be used to calculate the density and relative density of a substance.
   9. Density of ice is more than density of water.
   10. Iron nail will sink in water.
   11. A liquid seeks its own level.
   12. Liquids exert pressure on the base and walls of the container.
   13. A force requires only the magnitude to represent it.
   14. A man exerts same pressure on the ground whether he is standing or lying on it.
   15. The air pressure increases with the height.
   16. During the entire path of roller coaster, the total mechanical energy is conserved.
   17. The energy stored by an object due to its height in the gravitational field is the elastic potential energy.
   18. Kinetic energy of a body is directly proportional to the square of the speed of the body.
   19. The amount of work done depends on force applied and distance moved.
   20. A compressed spring has the potential energy because of its relaxed state.
   21. Refraction takes place at the two inclined surfaces of the prism and the light bends towards the third Surface (base) of the prism.
   22. The ratio of sine of angle of incidence to the sine of angle of refraction is always a constant for every medium.
   23. When the ray of light passes from glass to air, it bends away from the normal.
   24. A virtual image formed by a spherical mirror is always erect and situated behind the mirror.
   25. Prism produces seven colours namely VIBGYOR.
   26. In order to allow thermal expansion, the water and steam pipes have a U-bend.
   27. The increase in area is given as ΔL = ∝LΔT where a is termed as the coefficient of linear expansion.
   28. Gases expand more than solids and liquids when heated.
   29. The coefficient of superficial expansion can be defined as the increase in the volume per unit original area per unit rise in the temperature.
   30. Kerosene contracts on heating.
   31. Decibel is the unit of pitch of a sound.
   32. Compression and rarefaction are formed in a longitudinal wave.
   33. Only a tuning fork produces a monotone.
   34. More tight and small is the membrane, higher is the pitch of the sound.
   35. The surface area of the vibrating body does not affect the loudness of the sound.
   36. Electricity is of two types: current electricity and static electricity.
   37. The electrons are positively charged. the protons are negatively charged and the neutrons have no charge.
   38. In friction, charging an uncharged conductor takes place just by bringing a charged body in close vicinity but not making any physical contact with the uncharged body.
   39. When two objects are rubbed together, the free protons are transferred from one object to the another.
   40. A body having deficit electrons is said to be positively charged.
3. 3.

   The naphthalene balls disappear after some time. Give reason.

4. 4.

   Out of wood, gold and cotton, which solid is compressible?

5. 5.

   A gold chain is termed as solid. Why?

6. 6.

   Why does the water level does not rise when sugar is added to it?