Introduction to Electronics & Communication Engineering (Set-10)
What type of signal is used in digital communication systems?
A Sine
B Analog
C Continuous
D Binary
Digital communication systems use binary signals, which consist of two distinct levels (0 and 1). These signals are used to represent data in a form that is easy to process, transmit, and store in modern electronic systems.
What does modulation in communication systems achieve?
A Data transmission
B Signal encoding
C Signal amplification
D Noise reduction
Modulation is the process of encoding data onto a carrier signal by varying its amplitude, frequency, or phase. This allows the signal to be transmitted effectively over long distances and received accurately by the system.
Which modulation technique is commonly used in AM radio broadcasting?
A Time Modulation
B Frequency Modulation
C Amplitude Modulation
D Phase Modulation
Amplitude Modulation (AM) is widely used in radio broadcasting. It involves varying the amplitude of the carrier wave according to the information signal, such as audio signals in AM radio transmission.
Which component is commonly used for transmitting electromagnetic waves in wireless communication systems?
A Antenna
B Diode
C Resistor
D Capacitor
Antennas are used to transmit and receive electromagnetic waves in wireless communication systems. They convert electrical signals into radio waves for transmission and vice versa for reception, enabling wireless communication over various distances.
What is the primary function of a digital signal processor (DSP)?
A Generate power
B Store data
C Perform signal processing
D Amplify signals
A Digital Signal Processor (DSP) is designed to perform mathematical operations on digital signals, such as filtering, modulation, and compression. It is widely used in applications like audio processing, telecommunications, and image processing.
What is the function of a low pass filter in communication systems?
A Block high frequency signals
B Convert signals
C Amplify low frequency signals
D Modulate signals
A low pass filter allows low frequency signals to pass through while blocking high frequency signals. It is commonly used to eliminate unwanted high frequency noise in communication systems, ensuring clean signal transmission.
What is the advantage of using digital signals in wireless communication?
A Continuous amplitude
B Easier to process
C Higher noise susceptibility
D Lower data transfer rates
Digital signals are easier to process compared to analog signals because they are represented by discrete values (0s and 1s). This makes them more resistant to noise and easier to store, transmit, and manipulate.
Which device is responsible for converting digital signals into radio waves in wireless communication?
A Oscillator
B Antenna
C Transmitter
D Modulator
A transmitter converts digital signals into radio waves for transmission. It modulates the carrier wave with the digital data and sends the resulting electromagnetic signal to the antenna for wireless communication.
What is the main disadvantage of using high frequencies in communication systems?
A Higher power consumption
B Increased interference
C Limited bandwidth
D Shorter transmission range
Higher frequencies in communication systems tend to have shorter wavelengths, which results in a shorter transmission range. They are also more susceptible to attenuation and interference, making long distance transmission more challenging.
What is the role of a demodulator in communication systems?
A Decode data from a carrier wave
B Amplify signals
C Generate signals
D Filter noise
A demodulator decodes the modulated carrier wave to retrieve the original information. It reverses the modulation process, allowing the receiver to extract the transmitted data for further processing.