1.         The devastation of Islamic world by Chengiz Khan and Halaku Khan resulted in the Islamic World to lag behind in the scientific field.

2.         Pin hole cameral was invented by Ibn-al-Haitham.

3.         Aljabar-wal-Muqabla is the famous book of Alberuni.

4.         Mamun-ur-Rashid appointed Alkindi to translate the work of Aristotle and other Greek philosophers.

5.         Alberuni proposed that the Indus valley was the basin of an ancient ocean that has gradually dilled by mud.

6.         Naseer-ud-din Tussi had an observatory built at Maragha.

7.         The behaviour of atoms in the isolated states is studied under the branch of nuclear physics.

8.         The fundamental unit of time in S.I units is minute.

9.         The S.I unit of acceleration is meter per second square.

10.     1 nanosecond = 10^-8 second.

11.     Hundredth of a mm can not be measured correctly with a micrometer screw gauge.

12.     A physical balance is device used for measuring weight.

13.     The fundamental unit of length is centimeter.

14.     A force directed north may balance a force directed south.

15.     Two forces of different magnitudes and opposite in direction may balance each other.

16.     Two forces of the same magnitude but opposite direction must balance each other.

17.     Speed is a vector quantity.

18.     The process of splitting up a vector into two or more vectors is called resolution of vectors.

19.     The motion of a pendulum is an example of vibratory motion.

20.     The least distance from one point in the direction of another point is called displacement and it is a scalar quantity.

21.     The speed of a car moving on a straight road is decreasing on applying the brakes. It velocity and acceleration are in the same direction.

22.     The acceleration of a body moving with uniform speed in a circle is zero.

23.     The acceleration due to gravity for light bodies is less and large for heavy bodies.

24.     The speed and magnitude of velocity of bodies moving on a straight road are equal.

25.     A moving car comes to rest by the application of brakes. Its final velocity is zero.

26.     All the equations of motion represent the relations between four out of five quantities (v_i, v_f, a, t, s).

27.     Newton’s first law of motion is also known as law of inertia.

28.     The acceleration produced in a body under the influence of an external force is inversely proportional to the applied force.

29.     Mass is a vector quantity whereas weight is a scalar quantity.

30.     Friction is a self adjusting force which is equal to but in the opposite direction of the applied force just before the motion begins.

31.     The maximum force of friction is called limiting friction.

32.     The value of the limiting friction is inversely proportional to normal reaction.

33.     Had there been no friction it would bot have been possible to set a body in motion or to stop a moving body.

34.     The biggest disadvantage of friction is that some energy is continually being lost due to friction between some parts of the machines.

35.     The value of the coefficient of friction depends upon the nature of the surfaces in contact.

36.     It is wrong to say that mass is the measure of inertia.

37.     The first condition of equilibrium is that the algebraic sum of torques acting on a body in equilibrium is zero.

38.     If a body in a unstable equilibrium is slightly tilted , then its C.G is lowered.

39.     If the centre of the gravity of a body in equilibrium is lower than the point of suspension or support then it is in the state of unstable Equilibrium.

40.     A body is said to be in static position if it is at rest.

41.     The second condition of equilibrium is that the algebraic sum of all the torque acting on a body is zero.

42.     The centre of gravity of regular shaped objet lies at their edges.

43.     Law of gravitation is only applicable to the heavenly bodies.

44.     The acceleration due to gravity g varies inversely as the square of the distance of the body from the centre of the earth.

45.     The mass of the earth can be determined with the help of the law of universal gravitation.

46.     Centripetal Force is inversely proportional to the square of the mass of the body.

47.     While taking a turn on a horizontal road the centripetal force is provided to a car by the friction between the road and its tires.

48.     A body moving with a uniform speed on a circle has a uniform Velocity.

49.     Energy is an agent for change.

50.     Joule is the unit of power.

51.     Velocity is the rate of doing work.

52.     Potential energy of a body is the energy, which it acquires by virtue of its motion.

53.     When a simple pendulum swings, its total energy at the extreme point is wholly kinetic.

54.     For a screw jack the mechanical advantage is given by 2pd/h where d is the effort arm and h is the pitch of the screw.

55.     The efficiency of an inclined plane is increased when the angle it make with the horizontal is decreased.

56.     The mechanical advantage of a moveable pulley is four.

57.     The ratio of output and input in a machine is known as Mechanical Advantage.

58.     In a fixed pulley its block is connected from the weight.

59.     Rubber is more elastic than steel because we apply greater force to deform steel.

60.     Stress is a unit less quantity.

61.     The ratio of stress to strain is constant and is called modulus of elasticity.

62.     The force acting normally on a unit area is called pressure.

63.     Mass per unit volume of a body is known as density.

64.     In liquids the pressure at the same depth is not equal in all directions.

65.     The pressure inside a vessel containing gas is due to the weight of the gas.

66.     If the weight of a body is less than the upward thrust, the body will float on the surface of the liquid.

67.     Every substance has a definite density by which it can be identified.

68.     A solid object sinks in a fluid when the buoyancy force acting on the object is greater than the weight of the object.

69.     The average kinetic energy of the molecules of a body is proportional to temperature of the body.

70.     The increase in unit volume of a body per degree rise in its temperature is called the Co-efficient of volume expansion.

71.     At 4°C the volume of water is minimum and its density is maximum.

72.     The real expansion of liquid is less than its apparent expansion.

73.     Heat is such a form of energy which cannot be converted into mechanical energy.

74.     The moderate climate of regions near seas and lakes is due to the maximum specific heat of water.

75.     Heat which is given to a solid body while it is melting, it is used to over come the Beautiful force between its molecules, the temperature of the body is not increased by the absorption of this heat.

76.     Cooling is produced in the compressor of a refrigerator by the process of evaporation.

77.     A maximum minimum thermometer measures temperature over a limit of usually 35°C and 43°C.

78.     The temperature of a liquid remains constant during the process of evaporation.

79.     Amplitude is the distance between the extreme positions of a vibrating body.

80.     The time required to complete one vibration is called time period.

81.     The motion of the bob of a simple pendulum is not S.H.M.

82.     Force applied to a spring is inversely proportional to the extension in the string.

83.     As the waves pass over the surface of water, the particles of water start moving with the waves.

84.     The velocity of a wave is equal to the product of the frequency asnd wavelength of the wave.

85.     Wave length is the distance between two such consecutive particles of the medium which are in the similar state of their periodic motion.

86.     Wave is the only effective way of transferring energy from one place to another.

87.     The pitch of sound increases if the frequency of vibrating body is increased.

88.     Generally pitch of the sound of women is lower than the pitch of the sound of men.

89.     The characteristic of sound which helps us to distinguish the soundness of the same pitch and loudness is called the quality of sound.

90.     The frequency of a wave is directly proportional to its time period.

91.     It is due to irregular reflection of light that sunlight reaches us before sunrise and persists for sometime even after the sunset.

92.     In case of a convex mirror, for all object distances, the image formed is always real.

93.     Rays of light parallel to the principal axis after reflection from a concave mirror diverge.

94.     If the object is placed in front of a concave mirror at principal fucus F, the image is formed at infinity.

95.     In spherical mirrors, the radius of curvature is twice as large as its focal length.

96.     If a ray of light enters normally from one medium into the other then the angle of refraction is much larger than angle of incidence.

97.     One angle of the totally reflecting prism is 90° while the other two angles 45° each.

98.     The principal focus of a concave lens is always virtual.

99.     A virtual image is that which can be obtained on a screen.

100. The reciprocal of the focal length of a lens is called its power.

101. The unit of power of lens is dioptre.

102. Centre of curvature is the centre of that sphere of which the lens is a part.

103. The distance between the centre of curvature and the optical centre is called focal length.

104. The image formed by a concave lens is always real.

105. The principal focus of a convex lens is always real.

106. Total internal reflection always takes place when the angle of incidence is much less than the critical angle.

107. A simple microscope is a biconcave lens.

108. The image in the human eye is formed at the iris.

109. A compound microscope contains a convex and concave lens.

110. Infrared radiation stimulates the formation of vitamin D.

111. Due to atmospheric pollution the oxygen layer is being damaged day by day.

112. The frequency of visible light waves ranges from 0.1mm to 0.3mm.

113. Rainbow appears in the sky on the side opposite to where the sun is located.

114. White light is refracted while passing through a prism. The amount of refraction is not the same for all colours composing the white light.

115. The frequency of a photon of violet light is double than the frequency of a photon of a red light.

116. The mass of proton is 100 times larger than the mass of an electron.

117. Neutron is a particle which has a negative charge and its mass is equal to that of an electron.

118. The force between two charges varies directly as the square of the distance between them.

119. Repulsion is the sure test for a body being charged.

120. Objects build up a static charge when protons are lost from it due to friction.

121. Electric intensity at any point in an electric field is the force experienced by an electron placed at that point.

122. Generation of negative charges in a neutral body due to presence of a charged body near it is known as electrostatic induction.

123. The potential difference between two points in an electric field is that force exerted on a unit positive charge as it si moved between these two points.

124. The electron in metals which are not attracted to any particular atom are known as free electrons.

125. The flow of current in a metal is due to flow of protons.

126. Volt is the unit of electric current.

127. The conventional current always flows from a point at a higher potential to a point at lower potential.

128. The magnetic lines of force start from the south pole and end at north pole and they are continuous through the body of the magnet.

129. The magnetic lines of force can pass more easily through iron than air.

130. Faraday discovered a connection between electric curren and magnetism.

131. The magnetism of an electromagnet depends upon the number of turns and the magnitude of the current passing through the coil.

132. The magnetic field produced by a current passing through a solenoid is similar to a magnetic field due to a bar magnet.

133. If a current carrying conductor is held perpendicular to a uniform magnetic field, then no force acts upon it.

134. The working of a galvanometer depends upon the magnetic field of a permanent magnet and it’s interaction with the magnetic field produced round the current carrying wire.

135. A galvanometer having a shunt fitted parallel to it is called a voltmeter.

136. A galvanometer can be converted into an ammeter by connecting a wire of suitable resistance in series with it.

137. A good voltmeter is that voltmeter whose resistance is so high that a very small current passes through it.

138. Rubber, glass, mica, ceramic and plastics are good conductors.

139. Semi conductors are the elements in the group IV.

140. The electric current can hardly pass through the pn-junction if a semi conductors diode is forward biased.

141. Sound waves travel in space with the velocity of light.

142. Holes are the charge carrier in n-type material.

143. The nucleus of ²³⁸U₉₂ has equal number of protons and neutrons.

144. The emission of rays from radium is an example of atomic fussion.

145. b-particle is a nucleus of hydrogen.

146. g-rays carry positive charge.

147. The mass of helium nucleus is equal to the sum of the mass of two protons and two neutrons.

148. The splitting of nucleus of the atom is called fission.

149. The fusion process cntinues in the sun and other stars.