PHYSICS
1. (c); Echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The reflecting object must be more than 17m from the sound source for echo to be perceived by a person located at the source.
2. (b); A black board appears black because it absorbs all the colors of white light and reflects none.
3. (d); A tensiometer in soil science is a measuring instrument used to determine the Soil water tension. Such tensiometers are used in irrigation scheduling to help farmers and other irrigation managers to determine when to water. It can also be used in the scientific study of soils and plants.
4. (c); The SI unit of Force is Newton. One Newton. is equal to 1 kilogram meter per second squared.
5. (c); Glass is bad thermal conductor and is a good insulator. It has tightly held electrons which did not allow heat to flow through it.
6. (c); LASER (LIGHT AMPLIFICATION BY STIMULATED EMMISSION OF RADIATION) is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The first laser was built in 1960 by Theodore Theodore H. Maiman.
7. (b); An odometer or odograph is an instrument for measuring the distance travelled by a vehicle, such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two.
8. (c); The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N/m2, or kg.m-1.s-2). This name for the unit was added in 1971. It is named after the French polymath Blaise Pascal.
9. (a); When a beam pass of parallel light rays is incident on a smooth and plane surface, the reflected rays will also be parallel. This type of reflection is called Regular Reflection.
10. (a); The ohm (symbol: 2) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm.
11. (d); The value of Gravitational Force range from a minimum of 9.78 metre per second squared at the Equator to a maximum of 9.83 metre per second squared at the poles. Hence Gravitational Force is maximum on polls.
12. (b); A hygrometer is an instrument used for measuring the water vapour (humidity) in the atmosphere.
13. (d); Speed is the distance travelled by object in a certain interval of time. Speed is not dependent on direction hence it is a scalar quantity. While Displacement, Momentum and Torque has both magnitude and direction, so they are vector quantity.
14. (b); The temperature at which a liquid freezes is called the Freezing Point. The freezing point of water is 32°F.
15. (b); Newton’s first law is other name of Galileo’s law of Falling bodies. According to Law of Fall “The distance travelled by falling body is directly proportional to the square of the time it takes to fall”. This latter claim states that a body in motion will continue its motion so long as no factor disturbs that motion. This principle is called the principle of inertia which is basis of Newton’s first law.
16. (a); A pyrometer is a type of remote-sensing thermometer used to measure the temperature of a surface and inside metallurgical furnaces.
17. (d); In a qualitative way, a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force is called Inertia. In other words, the tendency of undisturbed objects to stay at rest or to keep moving with the same velocity is called Inertia.
18. (c); The time taken by a pendulum to complete one oscillation is called its Time Period.
19. (c); If the mass of an object is 60 kgs, 100N will be its weight on the moon. 20. (a); The convex mirror produces an upright image of any object and offers a wide viewing area as compared to the plane mirror. The usage of this type of mirror can be perceived on the car rear-view mirror, side-view mirror and even the motorcycles.
21. (a); If the speed of an object ‘moving along a straight line is constant, its motion is said to be uniform motion.
22. (d); The strength of a force is usually expressed by its Magnitude.
23. (a); Concave mirrors are used to provide a magnified and inverted image in rear view mirror.
24. (c); The Surface tension of water provides the necessary wall tension for the formation of bubbles with soap water. The tendency to minimize that wall tension pulls the bubbles into spherical shape.
25. (a); In absolute vacuum, there are no particles, no material medium, nothing. So, there is no reflection, refraction, diffraction, etc. That is why it travels the fastest in vacuum.
26. (c); The SI unit for measuring an electric current is the ampere, which is the flow of electric charge across a surface at the rate of one coulomb per second. Electric current is measured using a device called an ammeter.
27. (b); While frequency measures the cycle rate of the physical waveform, pitch is how high or low it sounds when you hear it. Pitch and Frequency are related to each other. A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave.
28. (c); The photoelectric effect is an phenomenon in which the emission of electrons occurs when a beam of light strikes a metal or a cathode surface. For emissions of electrons frequency of incident light is required to be greater than a minimum value called Threshold Frequency. Thus, show particle nature of light.
29. (b); An electric motor is an electrical machine that converts electrical energy into mechanical energy.
30. (a); Optical fibre work on the principle of Total Internal Reflection of Light. In optical fibre, when light traveling in an optically dense medium hits a boundary at a steep angle (larger than the critical angle for the boundary), the light is completely reflected. This is called total internal reflection.
31. (b); Water Tank appear shallower when viewed from the top due to refraction of light. This virtual depth is known as Apparent depth.
32. (b); Yellow colour is formed when Red and Green are mixed,
33. (d); Ultraviolet (UV) radiation from the sun or sunbeds is the main cause of skin cancer.
34. (b); It may seem that current is a vector because it have a magnitude and a direction. But the thing is, a vector always obey the law of addition of vectors. Since current doesn’t obey it and it follows algebraic addition, current is a scalar.
35. (a); The phenomenon of raising outer edge of the curved road above the inner edge is to provide necessary centripetal force to the. vehicles to take a safer turn and the curved road is called Banking of Roads.
36. (d); A convex mirror provides for a larger field of view than a plane mirror. They are used whenever a mirror with a large field of view is needed. For example, the passenger-side rear view mirror on a car is convex.
37. (c); Diffraction is defined as the bending of light around the corners of an obstacle or aperture into the region of geometrical shadow of the obstacle.
38. (d); Mirage formation is a result of the refraction and the total internal reflection of light in the air.
39. (c); It is difficult to fix a nail on a freely suspended wooden frame because when the wooden frame is not resting against a support, the frame and nails both move forward on being hit with a hammer. However, when the frame is held firmly against a support, and the nail is hit, an equal reaction of the support drives the nail into the frame. Thus based on Newton’s Third Law of Motion.
40. (b); Electromagnetic waves are propagated by oscillating electric and magnetic fields oscillating at right angles to each other. They are not deflected by electric or magnetic field. They can show interference or diffraction, are transverse waves, may be polarized and need no medium of propagation.
41. (c); Zacharias Janssen was a Dutch spectacle- maker from Middelburg associated with the invention of the first Optical telescope. He is also credited for inventing the first truly compound microscope.
42. (b); Supercooling is the process of chilling a liquid below its freezing point, without it becoming solid.
43. (a); Refraction is the bending of light as it passes from one medium to another. The bending is caused by the differences in density between the two substances.
44. (b); A H Taylor and Leo C Young are inventor of first true radar.
45. (a); Decibel (dB) is the SI unit of intensity of sound.
46. (a); When blue and green colour combine, the result is cyan.
47. (b); SI unit of power is watts. A watt is the power that it takes to do one joule of work in one second.
48. (d); Pascal’s principle states that “a change in the pressure of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container.” For every 10m depth the pressure on the diver increases by 1 atm so at a depth of 10 meters under water, pressure is twice the atmospheric pressure at sea level. Thus, during Scuba diving players must have the knowledge of Pascal’s law.
49. (b); Least distance of distinct vision is defined as the minimum distance between the eye lens and the object to form a clear image. For a healthy human eye, the least distance of distinct vision is 25 cm, however it varies with age.
50. (a); In 1742, Swedish astronomer, Anders Celsius invented the Celsius (Centigrade) temperature scale, which was named after the inventor.
51. (b); Pascal’s Law states that pressure that is applied to an enclosed fluid is transmitted equally to all other points. A hydraulic pump is a water pump that uses the kinetic energy of flowing water to force a small. fraction of that water to a reservoir at a higher level. The hydraulic lift works because of Pascal’s law. If force is put on(according to Pascal’s Law), that force should be entirely felt on all points throughout the liquid.
52. (a); At 40 degrees, the numerical values on Celsius and Fahrenheit scales become equal.
53. (c); Sublimation is the phase transition of a substance directly from the solid to the without passing through the intermediate liquid phase.
54. (a); When a ball is thrown vertically upwards, energy remains constant during its motion.
55. (a); Heat is the amount of energy that flows spontaneously from a warmer object to a cooler one. In SI system, heat energy is measured in joules (J).
56. (d); The Sun and the planets move around each other with their center of mass lying at the focus of the elliptical orbits. In other words, If the orbit of a planet is an ellipse then the point at which the Sun is located called Focus.
57. (d); The sliding friction is smaller than the static friction.
58. (d); The. Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics. The kelvin (symbol: K) is the base unit of temperature in the International System of Units (SI).
59. (a); Willem Einthoven electrocardiogram (ECG). invented the
60. (d); If the speed of an object moving along a straight line keeps changing with time then its motion is said to be non-uniform motion.
61. (b); A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move.
62. (a); Space pen is a ballpoint pen invented by Paul C. Fisher and made to work in zero gravity, underwater, and at any angle (even upside down). It is also known as Zero Gravity Pen and Fisher Space Pen.
63. (c); In the formula of average velocity = (u +v)/2, u is the initial velocity.
64. (c); If the force applied on the object is in the direction opposite to the direction of motion, the speed of the object decreases.
65. (a); The SI unit of acceleration is the meter per second squared.
66. (a); Contact force is another name for Friction.
67. (b); The force of friction between two surfaces will increase if the two surfaces are pressed harder.
68. (a); An image formed by a plane mirror, that cannot be obtained on a screen is called Virtual image.
69. (a); The force exerted by a magnet is an example of Non-contact force.
70. (b); Uniform motion is defined as the motion of an object in which the object travels in a straight line and its velocity remains constant along that line as it covers equal distances in equal intervals of time, irrespective of the length of the time.
71. (c); An image stays on the retina for about 1/16 of a second. This feature is called persistence of vision.
72. (c); Newton’s second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
73. (b); The coil wire is heating element in electric room heater or electric cooking heater to converts electricity into heat through the process of resistive or Joule heating. Electric current passing through the element encounters resistance, resulting in heating of the element.
74. (b); Energy in the form of heat is wasted when a machine is operated. This heat is generated due to Friction between two parts.
75. (c); The law of reflection states that the incident ray, the reflected ray, and the normal at the point of incidence all lie in the same plane.
76. (b); A concave mirror is capable of producing a real image.
77. (c); The distance-time graph for the motion of an object moving with a constant speed is a Straight Line.
78. (a); If the force applied on the object is in the add direction of its motion, the speed of the object increases.
79. (a); If an object moves in a circular path with uniform speed, its motion is called uniform circular motion.
80. (c); The reflection formed by the plane mirror is Lateral inversion.
81. (a); A ball rolling along the ground gradually slows down and finally comes to rest is due to friction.
82. (b); The angle between the Normal and the incident ray is called the angle of incidence. 83. (d); James Dewar was inventor of the thermos flask.
84. (a); Friction is caused by the irregularities on the two surface in contact.
85. (a); In general, a uniformly accelerated motion is the one in which the acceleration of the particle throughout the motion is uniform. The motion of a freely falling body is an example of Uniformly accelerated motion.
86. (b); The Melting point of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure.
87. (d); For an object, the state of rest is considered to be the state of zero speed.
88. (b); The laws which govern the motion of planets are called Kepler’s law of planetary motion.
89. (b); Concave and convex are two classes of spherical mirrors. A concave mirror is a spherical mirror in which the reflecting surface and the center of curvature fall on the same side of the mirror. On the other hand, a convex mirror is a spherical mirror in which the reflecting surface and the center of curvature lie on the opposite sides of the mirror.
90. (a); Drag is a kind of frictional force exerted by fluid which opposes the motion of an object through that fluid. Drag force acts in direction opposite to the direction of motion of the object.
91. (d); The SI unit of frequency is the hertz (Hz), named after the German physicist Heinrich Hertz; one hertz means that an event repeats once per second.
92. (b); Wood is a good insulator.
93. (b); Bubbles of air rise up through liquids due to viscosity and buoyancy.
94. (b); Wood is an insulator.
95. (c); Farsightedness (Hypermetropia) as it is medically termed is a vision condition in which distant object are usually seen clearly, but close ones do not come into proper focus. To remove this vision problem one should use a convex lens.
96. (d); When light from stars passes through the atmosphere, it bent due to refraction, which – is why stars seem to twinkle. Due to the planets’ closeness to Earth, the light coming from these celestial bodies does not bend much due to Earth’s atmosphere. Therefore, the light coming from our solar system’s. planets does not appear to twinkle like stars. 97. (a); The ‘Choke’ used with a tube light is basically an inductor. 98. (d); The transverse nature of light can. be demonstrated through polarization.
99. (c); Rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification, since it “straightens” the direction of current.
100. (c); Saw dust is used to cover ice because it is poor conductor of heat. It did not let the ice melt quickly, as it does not transfer the heat of the surrounding to the ice.
101. (d); The washing machine works principle of Centrifugation. on the
102. (d); In absence of earth’s atmosphere, sky would appear black due to absence of scattering phenomena.
103. (c); Temperature of distant luminous bodies can be determined by Pyrometers.’
104. (c); Energy travels from Sun to Earth through Radiation.
105. (b); Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in both conduction and convection.
106. (b); If electric resistance is to be decreased, then the number of resistances should be connected in Parallel.
107. (d); A transistor is a semiconductor device used as an amplifying device.
108. (a); The unit of measurement of Noise is Decibel.
109. (c); Total internal reflection is responsible for the glittering of air bubble rising through water.
110. (c); In an optical fibre the signal is transmitted due to total internal reflection.
111. (a); When we see an object, the image formed on the retina is real and inverted.
112. (d); The amount of translational kinetic energy that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object.
113. (b); Kinetic Energy is form of energy which is the supplied heat energy stored during change in temperature of substance.
114. (c); In order to convert a Galvanometer into voltmeter, a very high resistance known as “series resistance” is connected in series with the galvanometer.
115. (b); Even after sunset, the air near the Earth’s surface continue to receive heat due to Terrestrial Radiation.
116. (d); During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.
117. (b); At hill stations, the boiling point of water will be less than that at sea level due to change in atmospheric pressure.
118. (b); The component used for tuning a radio is basically a variable capacitor.
119. (b); 0°K is equivalent to – 273°C.
120. (d); Air is optically rarer than water, the ray of light bends away from the normal at the point of incidence when moving from water to air while it bends towards the normal. while moving from air to water. It is clearly visible that the air bubble acts as a DIVERGING LENS (concave lens) in water.
121. (a); DC implies no changes in value. Frequencies of signals are defined by how many changes per time, e.g. 60 cycles per second. In case of DC with there are 0 changes per second. Hence the frequency of DC is zero.
122. (c); The term ‘Higgs Boson’ is associated with God particle.
123. (c); Candela is not related to sound. It is unit of light intensity.
124. (c); electromagnetic radiation refers to the waves of the electromagnetic field, propagating through space-time, carrying electromagnetic radiant energy. It includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
125. (a); Graphite is a very good conductor of electricity due to the mobility of the electrons in its outer valence shells.
126. (b); A lactometer is an instrument used to check purity of milk.
127. (d); Diamond is a bad conductor of electricity but good conductor of heat. Electricity is conducted in a crystal by electrons that are relatively free. But in diamond, each carbon atom is covalently bonded with four other carbon atoms and there are no free electrons.
128. (c); Weightlessness experienced while orbiting the earth in space ships is due to Zero gravity.
129. (b); The sextant is an instrument used to measure angles. Mainly used at sea, the tool is so named because its arc is one sixth of a circle – 60 degrees.
130. (d); Since, the projectile is fired at an angle, its velocity can be split into two components – horizontal(Vx) and vertical(Vy). Vx=v*cosp Vy=v*sino
Gravity is the only force acting on it. And it is acting downwards, so only the vertical component of the velocity is affected by this and the horizontal component remains constant.
131. (d); Ultrasonic waves cannot be polarised, ultrasonic wave is an example of sound wave and it cannot be polarised.
132. (c); The color of a star which varies from bluish white and yellow to orange and red is primarily due to its composition and effective temperature.
133. (b); An anemometer is a device that is used to measure wind speed. There are many different types of anemometers suited for different environments.
134. (b); Blood pressure is measured by instrument called sphygmomanometer also called asblood pressure meter, it is used to measure the pressure of blood in Arteries.
135. (d); The reverse effect of X-ray emission is Photo-electric effect.
136. (d); Solar panels are those devices which are used to absorb the sun’s rays and convert them into electricity or heat. A solar panel is actually a collection of solar photovoltaic) cells. (or
137. (a); Visible light has the lowest frequency among the following electromagnetic radiations.
138. (b); The Theory of relativity is postulated by Albert Einstein.
139. (c); Fathometer is a depth finder that uses sound waves to determine the depth of water.
140. (a); Barograph was invented in 1844 by the Frenchman Lucien Vidi (1805-1866).
141. (c); Power is the ratio of two scalar quantities, and is thus scalar quantities.
142. (b); A Seismometer is an instrument that measures motion of the ground, caused by, for example, an earthquake, a volcanic eruption, or the use of explosives. It was invented by Italian scientist Luigi Palmieri.
143. (c); Newtons third law states that for every action there is an equal and opposite reaction.
144. (d); A Displacement is a vector whose length is the shortest distance from the initial to the final position of a point P. It quantifies both the distance and direction of an imaginary motion along a straight line from the initial position to the final position of the point.
145. (a); Cosmology is the study of the origin, evolution of the universe.
146. (a); When a ball is thrown upwards the acceleration due to gravity remains constant throughout. It comes to rest for a moment at the highest point of motion just before returning back to earth.
147. (d); When a body is moving on a circular path its average velocity when it complete one cycle in one second is zero.
148. (a); Evangelista Torricelli is universally accepted as inventor of Barometer. Charles Xavier Thomas invented mechanical calculator. Edward Teller is known as “the father of the hydrogen bomb”. Gustav Tauschek developed numerous improvements for punched card-based calculating machines.
149. (a); Newton’s First Law of Motion states that a body at rest will remain at rest unless an outside force acts on it, and a body in motion at a constant velocity will remain in motion in a straight line unless acted upon by an outside force.
150. (d); When an Object is dropped from height and when there is no air resistance the speed of object will increase.
151. (b); George Stephenson built the first steam locomotive to carry passengers on a public rail line, which is between Stockton and Darlington Railway in 1825.
152. (a); Distance=Speed × Time
153. (a); The mole is the unit of measurement for amount of substance in the International System of Units (SI). The unit is defined as the amount or sample of a chemical substance that contains as many constitutive particles.
154. (b); The Arithmometer was the first digital mechanical calculator strong enough and reliable enough to be used daily in an office environment. It was invented by Charles Xavier Thomas.
155. (a); If an object is thrown upwards its velocity will be 0m/s when it reaches at it maximum height.
156. (d); Momentum will be same for object having different masses for the force acting for same amount of time.
157. (a); Telephone exchange was invented by Tivadar Puskas.
158. (b); Two Positive charge will repel to each other so the force will decrease between two positive charge.
159. (d); A seismometer is an instrument that measures motion of the ground, caused by, for example, an earthquake, a volcanic eruption, or the use of explosives.
160. (b); “The ocean looks blue because red, orange and yellow (long wavelength light) are absorbed more strongly by water than is blue (short wavelength light). So when white light from the sun enters the ocean, it is mostly the blue that gets returned.
161. (a); John Logie Baird was a Scottish engineer, innovator, one of the inventors of the mechanical television, demonstrating the first working television system on 26 January 1926.
162. (a); An electroscope is an early scientific instrument that is used to detect the presence and magnitude of electric charge on a body. It was the first electrical measuring instrument. The first electroscope, a pivoted needle called the versorium, was invented by British physician William Gilbert around 1600.
163. (d); Wavelength of red colour is largest and violet colour has the shortest wavelength.
164. (a); Glass is sometimes called a super cooled liquid because it does not form a crystalline structure, but instead forms an amorphous solid that allows molecules in the material to continue to move.
165. (b); Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
166. (c); In a streamline flow, velocity at every point in the fluid remains same.
167. (b); Postage Meter was invented by Arthur Pitney.
168. (b); Igor Sikorsky, a Russian is recognized as father of modern helicopters.
169. (b); The water level remains the same when the ice cube melts. A floating object displaces an amount of water equal to its own weight. Since water expands when it freezes, one ounce of frozen water has a larger volume than one ounce of liquid water.
170. (b); A scalar quantity is a one dimensional measurement of a quantity, like temperature, or weight, it has only magnitude and no direction.
171. (b); Angular momentum is a vector quantity.
172. (c); When the ice melts to liquid water, the structure collapses and the density of the liquid increases. At temperatures well above freezing, the molecules move faster and get further apart. The density decreases as temperature increases thus, the density of water is a maximum at 4 deg C.
173. (a); Work done due to displacement caused by a force is a scalar quantity.
174. (b); Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration.
175. (b); ON September 10, 1846, Elias Howe was granted a US patent for his invention of the sewing machine.
176. (a); The impulse-momentum theorem states that the change in momentum of an object equals the impulse applied to it.
177. (a); ISRO built India’s first satellite known as Aryabhata.
178. (c); Acceleration due to gravity, g = (GM) / R * 2. Thus, Acceleration due to gravity at a distance 2R, g’ = (GM) / (2R + R) * 2 = (GM) / 9 R2 = g / 9 (Since g = \{GM\} / R * 2 )
179. (a); Pascal is not unit of Moment of Inertia. Moment of inertia may be expressed in units of kilogram metre squared (kg. m2) in SI units.
180. (a); Atmospheric pressure is measured by Barometer.
181. (c); Hyetometer is the instrument used to measure rainfall.
182. (a); Max Planck was a German theoretical considered to be the initial founder of quantum theory, and one of the most important physicists of the 20th Century.
183. (c); In physics, spin is the velocity of rotation of something around a particular axis.
184. (b); If an object, on a free fall from a certain height, reaches the ground in 1 second, its velocity on the impact with the ground 9.8 m/s.
185. (d); The Orbital Motion Interactive is simulates the elliptical motion of a satellite around a central body. In this type of motion axis of the rotation does not pass through the object.
186. (b); Spin and Orbital motion are the two kinds of Rotatory motion.
187 (a); The moment arm or lever arm is the perpendicular distance between the line of action of the force and the center of moments. Moment Armis the perpendicular distance between point of application of force and axis of rotation.
188. (b); Longsec is not the unit of distance.
189. (c); The apparent weight of a person in a lift which is moving down with uniform acceleration is less than the weight when the person is stationary.
190. (c); Robert Hutchings Goddard (October 5, 1882 August 10, 1945) was an American engineer, professor, physicist, and inventor who is credited with creating and building the world’s first liquid-fueled rocket.
191. (d); Weight of a person at a height of 2R from the centre of the earth, where R is the radius of the earth became one-fourth.
192. (d); A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids. It is also used to measure specific gravity of milk.
193. (a); Enrico Fermi was an Italian-American physicist and the creator of the world’s first nuclear reactor, the Chicago Pile-1. He has been called the “architect of the nuclear age” and the “architect of the atomic bomb”.
194. (a); The angle between centripetal acceleration and tangential acceleration is 90°.
195. (c); A rectifier is an electrical device composed of one or more diodes that converts alternating current (AC) to direct current (DC).
196. (d); The Nobel Prize in Physics 1930 was awarded to Sir Chandrasekhara Venkata Raman “for his work on the scattering of light and for the discovery of the effect named after him.
197. (b); The Siemens (symbol S) is the derived unit of electric conductance.
198. (c); The rate of change of momentum of an object is directly proportional to the resultant force applied and is in the direction of the resultant force. The resultant force is equal to the rate of change of momentum.
199. (a); Scottish inventor and veterinary surgeon John Boyd Dunlop developed the pneumatic (air-filled) rubber tire. He was one of the founders of the rubber company that bore his name, Dunlop Pneumatic Tyre Company. In 1888, Dunlop patented his pneumatic tyre.
200. (b); When net torque is zero, angular momentum will be constant.
