Physics Section 1

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• SI unit of Heat is Joule.
• Two automobiles meet in 1.5 hours.
• The branch of science dealing with matter and energy is Physics.
• Physics is a branch of Physical sciences.
• Physics plays an important role in engineering.
• Physics provides fundamental laws to other sciences.
• Plasma physics deals with highly energetic ions.
• Nuclear Physics deals with nuclear particles.
• Field theory deals with properties of gravitational.
• The branch of physics dealing with living things is biological sciences.
• SI unit of Heat is Joule.
• Two automobiles meet in 1.5 hours.
• The branch of science dealing with matter and energy is Physics.
• Physics is a branch of Physical sciences.
• Physics plays an important role in engineering.
• Physics provides fundamental laws to other sciences.
• Plasma physics deals with highly energetic ions.
• Nuclear Physics deals with nuclear particles.
• Field theory deals with properties of gravitational.
• The branch of physics dealing with living things is biological sciences.
• Physics of moving charge particles is Electro-dynamics.
• Study of living science relates to Biological science.
• The first book of Physics was written by Aristotle.
• Photon is massless.
• Acoustics deals with the study of sound and sound waves.
• Formula of inter-conversion of centigrade and Fahrenheit scale is f -32/9 = c/5.
• Coefficient of linear expansion is ΔL = αLΔT.
• Unit of coefficient of linear expansion or volume expansion is K-1.
• Linear expansion occurs in solid.
• In motion, the position vector always changes.
• When in a car moving at constant velocity, speed with respect to car is zero.
• Area under velocity-time graph represents displacement.
• Instantaneous and average velocities become equal when the body has zero acceleration.
• Inertia of an object is a quantitative measure of its mass.
• 1st law of motion gives the definition of force.
• 3rd law of motion explains the existence of pair of forces in nature.
• The dimension of force is MLT-2.
• Force and acceleration have the same direction.
• Inelastic collisions conserve momentum but change kinetic energy.
• Centrifugal force makes passengers feel outward in a turning car.
• Velocity-time graph for constant acceleration is a straight inclined line.
• Fundamental frequency of open and closed pipe are related by fopen = 2 fclosed.
• Taking off rocket can be explained by the Law of conservation of momentum.
• Angle of projection for range and max height to be equal is tan-1 4.
• Distance covered by a freely falling body in 2 seconds is 19.6 m.
• Flight of a rocket in space is an example of the third law of motion.
• Angle at which the range of projectile is maximum is 45 degrees.
• Time rate of change of momentum is equal to force.
• Ballistic missiles may fail in precision due to air resistance.
• Displacement from origin changes when a body in motion has uniform velocity.
• When velocity-time graph is a straight line parallel to time axis, acceleration is zero.
• Slope of velocity-time graph is acceleration.
• First law of motion is also called the law of inertia.
• Newton’s laws don’t apply to particles moving with velocity comparable to velocity of light.
• Second law of motion gives the definition of acceleration.
• Momentum depends on mass and velocity of the body.
• When body moves in a straight line, displacement coincides with distance.
• Motorcycle safety helmet decreases force acting in a collision, decreasing impulse.
• Athlete increases momentum by running before a long jump.
• A falling body covers 14 meters during 1 to 2 seconds.
• In an inelastic collision, kinetic energy changes but momentum remains conserved.
• Rocket’s acceleration is proportional to the velocity of expelled gases.
• Gas-filled balloon doesn’t exhibit projectile motion.
• Thrust on the rocket in the absence of gravitational force is constant.
• The speeds of two objects are 5m/s and 1m/s.
• Distance covered by a body starting from rest in time t is at^2/2.
• Trajectory of a projectile is a parabola.
• Force by a wall when water strikes at 10m/s is 1 N.
• The ranges of projectiles at 30 and 60 degrees are equal.
• Waves transmit energy from one place to another.
• The distance between consecutive crests or troughs is called wavelength.
• Points with maximum amplitude in vibrating cord are antinodes.
• A stationary wave in a closed pipe has a node at the closed end.
• Speed of sound is greatest in copper.
• Velocity of sound in vacuum is zero.
• The speed of sound in air becomes four times in hydrogen.
• Speed of sound increases with temperature rise by 819°C.
• Ultrasonic waves have a frequency greater than 20 kHz.
• Beats are the result of constructive and destructive interference.
• Silence zones are due to destructive interference.
• When a source moves away, the apparent frequency of sound decreases.
• Fundamental frequency of open and closed pipe is related by fopen = 2 fclosed.
• Newton estimated the speed of sound to be 281 m/s.
• The speed of sound in hydrogen is four times that in oxygen.
• The speed of waves in a stretched string is independent of the number of loops and the point where the string is plucked.
• Doppler effect applies to both sound and light waves.
• Mechanical waves require a material medium for their propagation.
• The velocity of the resultant wave formed by superimposing two identical waves remains unchanged.
• Increasing the stretching force T of a wire increases its frequency.
• Transverse waves can be distinguished from longitudinal waves by the property of polarization.
• Sound waves do not travel in vacuum because they require a material medium for propagation.
• The increase in velocity of sound in air for a 1°C rise in temperature is 0.61 m/s.
• Loading the prong of a tuning fork with wax decreases its frequency.
• The normal ear is most sensitive in the frequency range of 2000 to 4000 hertz.
• Velocity of sound in air becomes double its value at 0°C at 819°C.
• Sonic boom is produced by an aircraft moving at a speed greater than the speed of sound.
• Resonance causes an increase in amplitude and sound intensity.
• Ultrasonic waves are used in industries for flaw detection.
• The refractive index of a medium is inversely proportional to the speed of light in that medium.
• The critical angle is the angle of incidence that results in an angle of refraction of 90 degrees.