## Physics Section 10

- The dimensions of the coefficient of viscosity are ML^-1T^-1.
- Terminal velocity is both uniform and maximum.
- When the body moves with terminal velocity, the acceleration in the body becomes 0.
- Terminal velocity is given by the equation Vt = 2gr^2/9ρ.
- Terminal velocity of the body is directly proportional to the square of the diameter of the body.
- The flow of an ideal fluid is streamline.
- The drag force is given by Stokes law.
- When a fluid is incompressible, the density of the fluid is constant.
- Irregular flow of fluid is called turbulent.
- According to the equation of continuity, A1V1 = A2V2 = flow rate.
- The equation of continuity is obtained by applying the law of conservation of mass.
- Velocity of fluid increases where the pressure is low.
- Speed of efflux can be determined by applying Torricelli’s theorem.
- Blood vessels are not rigid.
- Concentration of red cells in blood is about 50%.
- A man standing near a fast-moving train may fall towards the train.
- For which position does the maximum blood pressure in the body have the smallest value? Laying horizontally.
- Two fog droplets with radii 2:3 have terminal velocities of 4:09.
- Bernoulli’s equation is obtained by applying the law of conservation of energy.
- Venturi meter is used to measure fluid pressure.
- In cricket, when a bowler produces reverse swing, the ball will move towards the shining side of the ball.
- Stokes law is applicable if the body has a spherical shape.
- One torr is equal to 133.3 Nm^-2.
- Systolic pressure is high blood pressure.
- The instrument used to measure blood pressure is called a sphygmomanometer.
- A chimney works best if the air exposed to the chimney is moving fast.
- The effect of the decrease in pressure with the increase of the speed of the fluid in a horizontal pipe is known as the Venturi effect.
- Ideal fluid possesses all properties.
- Venturi relation is P1 – P2 = 1/2 ρV^2.
- Laminar flow usually occurs at low speeds.
- Sphygmomanometers measure blood pressure dynamically.
- The carburettor of a car is an application of Venturi meter and Bernoulli equation.
- Blood flow is laminar at systolic pressure.
- The profile of an airplane wing that lifts it up is called an aerofoil profile.
- Bernoulli’s equation is applicable for both laminar and turbulent flow.
- The density of human blood is nearly equal to water.
- The speed of the fluid is maximum in the venturi meter at the throat.
- The normal blood pressure range for a human body is 120 to 80 torr.
- For turbulent flow, the path of the fluid particles cannot be tracked.
- In vibratory motion, total energy remains constant.
- The waveform of simple harmonic motion is a sine wave.
- The SI unit of frequency is Hertz.
- In S.H.M., the velocity of a particle is maximum at the mean position.
- The acceleration of a projection on the diameter for a particle moving along a circle is w^2x.
- The total energy of a body executing S.H.M is directly proportional to the square of an amplitude.
- The time period of a second pendulum is 2 seconds.
- The length of the second pendulum is 99.2 cm.
- If the length of the second pendulum becomes four times, then its time period will become 2 times.
- The force responsible for the vibratory motion of the simple pendulum is mg sinθ.
- The frequency of the second pendulum is 0.5 hertz.
- Simple harmonic motion is a type of vibratory motion.
- The SI unit of force constant is identical with that of surface tension.
- When the amplitude of a wave becomes double, its energy becomes four times.
- A simple pendulum suspended from the ceiling of a lift has an infinite time period when the lift falls freely.
- The energy of SHM is maximum at all positions during SHM.
- The product of the frequency and time period is equal to 1.
- The length of the second pendulum is 99.2 cm.
- If the displacement of SHM is written as X = X’sinθt, then the phase constant will be 90°.
- For what displacement does the P.E become 1/4 of its maximum value? x = x’/2.
- The bulb does not work according to resonance.
- The restoring force acting on the simple pendulum is caused by gravity.
- The phase of SHM describes both displacement and direction of motion.
- The sharpness of resonance is inversely proportional to the damping force.
- The natural frequency of a simple pendulum depends on the square root of its length.
- Electrical resonance is observed in radios.
- The total distance traveled by a bob of the simple pendulum in one vibration is 4 times the amplitude.
- When K.E energy of SHM is maximum, all P.E, acceleration, and restoring force are zero.
- In damped harmonic oscillation, both amplitude and energy decrease.
- Forced vibration is known as driven harmonic vibration.
- The mass attached to a spring executes both vibratory and circular motion.
- At Murree Hills, if we use a simple pendulum as a time standard, one-second duration will increase.
- The velocity of the mass attached to a spring is maximum at the mean position.
- The projection of the particle moving in a circle with non-uniform speed executes both vibratory motion and none SHM.
- The displacement of the body in S.H.M is equal to the amplitude when the body is at the extreme position.
- For a simple pendulum, the restoring force is caused by gravity.
- The distance covered by a body in one complete vibration is 5 cm, so the amplitude is 5 cm.
- In a microwave oven, milk will be heated up only, and the cup will remain cool.
- In case of a simple pendulum, the cause of damping is the drag force of air.
- The energy absorbed by a body is maximum at resonance.
- The relativistic energy E is equivalent to relativistic mass given by E/c^2.
- γ-rays have the strongest photons among the provided radiations.
- The mass of 0.001 kg is equivalent to 25.00 GWh.
- Newton’s laws of motion are not valid in an accelerated (non-inertial) frame of reference.
- The wavelength of a photon entering a transparent denser medium is shorter, so its energy remains the same.
- The linear momentum of a photon is zero.
- Stopping potential for a metal surface in case of photoelectric emission depends on the frequency of incident light and work function of the metal surface.
- The change in wavelength is maximum in Compton scattering if the angle of scattering is 180°.
- The existence of Ether wind was experimentally rejected by the Michelson-Morley experiment.
- The rest mass of a photon is zero.
- Einstein’s photoelectric equation is given by 1/2 mvmax^2 = hf – Φ.
- The velocity of light entering into a denser medium decreases, and thus the energy of light remains the same.
- Rest mass of a photon is zero.
- Relativistic energy E is equivalent to relativistic mass given by E/c^2.
- The relativistic energy E is equivalent to relativistic mass given by E/c^2.
- A photon is a quantum of electromagnetic radiation.
- Davison Germer experiment indicates electron diffraction.
- A photon is a quantum of electromagnetic radiation.
- 103 photons of wavelength 2 pm (γ-rays) have the largest energy content.
- The rate of emission of photons is speed of light.
- The energy of light remains the same after traveling through a vacuum and entering a transparent denser medium.