Understanding Wave Properties

• Here are study notes based on the questions provided

Waves

• Polarization is not a property of longitudinal waves.
• Amplitude is the maximum displacement of particles from their equilibrium position.
• The characteristic of waves which enables one to differentiate a high note from a low note is pitch.
• If V is the velocity of a wave, Ἆ is its wavelength, and T is its period, the relationship among V, Ἆ, and T is V = Ἆ/T.
• Transverse and longitudinal waves traveling in the same direction in a medium differ essentially in the direction of vibration of the particle of the medium.
• For a wave of wavelength 0.3m traveling 900m in 3.0s, its frequency is 1000Hz.
• In the progressive wave equation Y = A sin(150πt – πχ/4), if the phase difference of the progressive wave is 45°, the value of x in the equation is 2cm.
• For a wavelength of 60cm, the distance between consecutive antinodes XX is 30cm.
• Reflection involves the change in the direction of waves when they bounce off a barrier.

Levers and Machines

• A plier is not a simple example of a first-order lever.
• A forearm is an example of a third-class lever.
• A lever whose effort is between the fulcrum and the load is called a third-class lever.
• The velocity ratio of an inclined plane whose angle of inclination is 30° is 2.0.
• In a plier, the effort is applied between the load and the fulcrum.
• For a machine with a velocity ratio of 2 that raises a load of 200N through a vertical distance of 2m, and the amount of work required by the machine is 400J, the efficiency of the machine is 100%.
• In a machine, the mechanical advantage is equal to the velocity ratio when the efficiency is 100%.
• For a radio wave of wavelength 600m, the frequency of the wave, given that the velocity of all electromagnetic waves in space is 3 x 10⁸ m/s, is 0.5MHz.
• A plane inclined at an angle of 30° to the horizontal with an efficiency of 50% requires a force parallel to the plane of 120N to push a load of 120N uniformly up the plane.
• A wheel and axle with radii 80cm and 10cm respectively, and an efficiency of 0.85, using an applied force of 1200N to the wheel will raise a load of 8160N.
• The velocity ratio of a screw jack of pitch 0.3cm if the length of the Tommy bar is 21cm is 140π.

Thermodynamics

• On the absolute scale of temperature, 273k is the ice point.

Instruments

• A guitar is NOT an example of a wind instrument.

Optics

• For a man 1.8m tall standing 3m away from a pinhole camera, if the distance between the pinhole and the screen of the camera is 0.3m, the height of the image of the man produced by the camera is 0.18m.
• For a ray of light that makes an angle of 35° with a plane mirror, the angle of reflection is 35°.
• An object is placed between two mirrors which are inclined at an angle of 120° and facing each other,3 images will be observed in the two mirrors
• Interference is a consequence of superposition of waves.
• Electromagnetic waves are transverse waves
• If a ray of light is incident on a plane mirror at an angle of 30°, the angle which the reflected ray makes with the surface of the mirror is 60°.
• The image in a pinhole camera is always inverted.
• An object is placed between two mirrors which are inclined at an angle of 90° while facing each other. The number of images formed by the two mirrors are 3.
• The distance between two points in phase on a progressive wave is 5cm. if the speed of the wave is 0.2m/s, calculate its period of 0.25s
• The distance between two successive crests of a water wave is 1m. If a particle on the surface of the water wave makes two complete vertical oscillations in one second, calculate speed of the wave of 2.0m/s
• Radio wave has a velocity of 3 x 10⁸m/s. A radio station sends out a broadcast on a frequency of 800 KHz. The wavelength of the broadcast is 375m
• A ray of light strikes a plane mirror at a glancing angle of 50º. The angle between the incident and reflected rays is 80°
• An object is placed in front of two plane mirrors inclined at an angle of º. If the total number of images formed is 7, find the value of 30°
• Calculate the position of an object placed in front of a convex mirror having a focal length of 12cm such that an image is formed 6cm away from the mirror. Value is 12cm
• Centre of Curvature represents the centre of the sphere of which the mirror forms a part.
• A place of grey shadows best defines a penumbra
• A road sign is a Non-luminous object
• Loudness of sound depends on Intensity