Sonography is an ultrasound-based diagnostic imaging technique used for visualizing internal body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions. In physics, 'ultrasound' refers to sound waves with a frequency too high for humans to hear.

Correct Option: D

Sonography is an ultrasound-based diagnostic imaging technique used for visualizing internal body structures including tendons, muscles, joints, vessels and internal organs for possible pathology or lesions. In physics, 'ultrasound' refers to sound waves with a frequency too high for humans to hear.

A body moving with a constant speed in a circle is an example of uniform circular motion. The velocity vector is constant in magnitude but changing in direction. Since velocity is a vector quantity that has both magnitude and direction, a change in either the magnitude or the direction constitutes a change in the velocity which leads to change in acceleration.

Correct Option: D

A body moving with a constant speed in a circle is an example of uniform circular motion. The velocity vector is constant in magnitude but changing in direction. Since velocity is a vector quantity that has both magnitude and direction, a change in either the magnitude or the direction constitutes a change in the velocity which leads to change in acceleration.

The maximum density of water occurs at 4 °C because at this temperature two opposing effects are in balance. Water is an exceptional compound that has a lower density in the solid phase than the liquid phase (i.e., ice floats on water). This is actually due to the ion nature of water in the liquid phase, which packs the molecules tightly together.

Correct Option: C

The maximum density of water occurs at 4 °C because at this temperature two opposing effects are in balance. Water is an exceptional compound that has a lower density in the solid phase than the liquid phase (i.e., ice floats on water). This is actually due to the ion nature of water in the liquid phase, which packs the molecules tightly together.

The formula of frequency is: f = c / ë = wave speed c (m/s) / wavelength ë (m), where f: frequency, c: wave speed, and ë: wavelength. As per the question, f = 300/0.3 = 1000 cycles/ seconds = 1000 Hz = 1 KHz
Sound waves with frequencies above 20 KHz are called Ultrasonic; those below 20 Hz are called Infrasonic. Sound waves with frequencies between 20 Hz to 20,000 Hz are called audible waves.

Correct Option: A

The formula of frequency is: f = c / ë = wave speed c (m/s) / wavelength ë (m), where f: frequency, c: wave speed, and ë: wavelength. As per the question, f = 300/0.3 = 1000 cycles/ seconds = 1000 Hz = 1 KHz
Sound waves with frequencies above 20 KHz are called Ultrasonic; those below 20 Hz are called Infrasonic. Sound waves with frequencies between 20 Hz to 20,000 Hz are called audible waves.

The micrometer or micron, is an SI derived unit of length equaling 1×10^–6of a metre, i.e., one millionth of a metre. It is a common unit of measurement for wavelengths of infrared radiation as well as sizes of cells and bacteria and is commonly used in plastics manufacturing.

Correct Option: C

The micrometer or micron, is an SI derived unit of length equaling 1×10^–6of a metre, i.e., one millionth of a metre. It is a common unit of measurement for wavelengths of infrared radiation as well as sizes of cells and bacteria and is commonly used in plastics manufacturing.