NCERT Solutions for Class 12 Sociology Part 2 Chapter 7 MCQ

The modulation index of an amplitude modulated signal is defined because the measure or extent of amplitude variation about un- modulated carrier. In other words the modulation index describe the number by which the modulated carrier envelope varies about static level.

Amplitude modulation is technique utilized in transmission most ordinarily for transmitting message with a video wave. In modulation the modulation of wave is varied in proportion to it of the message signal like audio signal.

Signal which require to be transferred are superimposed on high frequency wave which is termed radio emission because the name suggest it carries the signal.

A digital signal may be a signal that represent data as a sequence of discrete values, at any given time it can only tackle, at most one in all the finite number of values.

Varies directly as frequency deviation and inversely because the modulating frequency The FM modulation index is adequate to the ratio of the frequency deviation to the modulating frequency. From the formula and deviation of the modulation index ,it are often seen that there’s no term that include the carrier frequency and this suggests that’s totally independent of the carrier frequency.

Frequency modulation is that the encoding of data during a radio emission by caring the instantaneous frequency of the wave. The wave technology is employed in telecommunications, radio broadcasting signal processing and computing.

A communication satellite transponders is that the series of interconnected unit that fro a channel between the receiving and therefore the transmitting antenna .it is mainly utilized in satellite communication to transfer the received signal.

Digital data is transmitted via a television we all know that digital signal required higher bandwidth than analog signal. Space wave communication is employed for transmission of frequency over 30 MHz Thus the frequency range used for TV transmission is 30MHz-300MHz.

Attenuation is that the reduction of the amplitude of a sign electrical phenomenon or other oscillation the merchandise are used mostly by aircraft manufacturing for noise attenuation in engine housings.

The UV rates are expending their energy and therefore the different wavelength. The various layer in atmosphere are caused by different wavelength of the rates thus different ionosphere layer is high variable source of ionizing agent, solar wind.

A radio or radar set that upon receiving a design signal emits a radio emission of its own which is employed to especially for the detection, identification, and locations of object and in satellite for relaying communication signal.

An antenna may be a metallic structure that captured and or transmitted radio em waves antenna comes altogether shape and size from little ones which will be found on your roof to observe TV to actually big ones that capture signal from satellite million of miles away.

Microwave need to be utilized in line of sight communication, but due to earth curvature it’s impossible to hide larger area to increase the world repeater are to be used 50 km apart.

Optical communication employs a beam of modulated monochromatic light to hold information from transmitters to receiver .the light spectrum spans an amazing zero in the em spectrum extending from the region of 10 terahertz to 1 millions terahertz.

20Hz to 20000Hz is that the commonly referenced frequency range .however the common human can hear but this 20 Hz to twenty kHz range and individual age ,this detectable range only still shrink.

The first mass media institution began with the event of the printing press .Although the history of print in certain societies dates back ti many centuries. The primary attempts at printing books using modern technologies began in Europe