Collection of verified questions for Dhwani under General Science. Includes previous year exam questions with official answer keys and step-by-step solutions.
When a TV switch is turned on:
Assertion (A): Reverberation is particularly prominent in large churches and other spacious halls. Reason (R): Multiple reflections of sound can take place from the walls, ceiling, and floor. Code:
The technique used to transmit audio signals in television broadcasts is:
A noise loudness level of 100 decibels corresponds to:
Consider the following statements: 1. The widely used musical scale, called diatonic scale, has seven frequencies. 2. The frequency of the tone 'Sa' is 256 Hz and that of tone 'Ni' is 512 Hz. Which of the statements given above is/are correct?
When the same musical note is played on a sitar and a flute, the produced sounds can be distinguished from each other because of difference in:
The standard sound level for human beings is:
Sound above what decibel level is considered hazardous noise pollution?
A laborer is working on a railway track. A boy standing some distance away puts his ear to the steel rail and hears the hammer blows twice. This is because:
Which of the following has the longest wavelength?
Which of the following electromagnetic radiations is used for remote control of television?
Which one of the following is used by a TV remote control unit to operate a TV set?
Assertion (A): Radio waves bend in a magnetic field. Reason (R): The nature of radio waves is electromagnetic. In the context of the two statements, which of the following is correct? Code:
The tolerance limit of noise for humans is approximately:
Which of the following statements regarding sound waves is/are correct? Statement I: When we go from solid to gaseous state, the speed of sound decreases. Statement II: In any medium, as we decrease the temperature, the speed of sound increases. Statement III: The speed of sound in aluminum is less than in glass.
In television broadcasting, picture signals are transmitted by:
A radio station broadcasts at a 30-meter band. The frequency of the carrier waves transmitted by this station is:
What type of electromagnetic radiation is used in the remote control of a television receiver?
Which type of electromagnetic radiation is used in the remote control of a television?
According to the World Health Organization (WHO), the safe noise pollution level for a city is:
In a sitar, what type of sound vibrations are produced in the string?
The waves used in a common TV remote control are:
A biological method in which ultrasonic sound is used is:
Consider the following statements: 1. The heart vibrates at infrasonic frequencies. 2. The speed of sound is more in gas than in liquid and solid. 3. Mach number is used to describe the speed of sound. 4. Ultrasonic sound has a frequency of more than 20,000 Hz. Of these statements:
Sound waves-