Arrange the following electromagnetic radiations per quantum in the order of increasing energy:
A: Blue light
B: Yellow light
C: X-ray
D: Radiowave
D, B, A, C
A, B, D, C
C, A, B, D
C, A, B, D
Choose the correct statement:
In amplitude modulation, the amplitude of the high-frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.
In amplitude modulation, the frequency of the high-frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.
In frequency modulation, the amplitude of the high-frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.
In frequency modulation, the amplitude of the high-frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.
A signal of 5 kHz frequency is amplitude modulated on a carrier wave of frequency 2 MHz. The frequencies of the resultant signal is/are:
2005 kHz, and 1995 kHz
2005 kHz, 2000 kHz and 1995 kHz
2000 kHz and 1995 kHz
2000 kHz and 1995 kHz
A train is moving on a straight track with speed 20 ms-1 .It is blowing its whistle at the frequency of 1000 Hz. The percentage change in the frequency heard by a person standing near the track as the train passes him is (speed of sound = 320 ms-1 ) close to :
6%
12%
18%
18%
A diode detector is used to detect an amplitude modulated wave of 60% modulation by using a condenser of capacity 250 pico farad in parallel with a load resistance 100 kilo ohm. Find the maximum modulated frequency which could be detected by it.
10.62 MHz
10.62 kHz
5.31 mHz
5.31 mHz
A radar has a power of 1 Kw and is operating at a frequency of 10 GHz. It is located on a mountain top of height 500 m. The maximum distance upto which it can detect object located on the surface of the earth (Radius of earth = 6.4 x 106 m) is
80 km
16 km
40km
40km
This question has Statement 1 and Statement 2. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement 1 - Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals.
Statement 2- The state of ionosphere varies from hour to hour, day to day and season to season.
Statement 1 is true, statement 2 is false.
Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of Statement 1
Statement 1 is true, Statement 2 is true, Statement 2 is not the correct explanation of Statement 1
Statement 1 is true, Statement 2 is true, Statement 2 is not the correct explanation of Statement 1
A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of
1000
10000
10
10
In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be
50 Hz
25 Hz
100 Hz
100 Hz
A telephonic communication service is working at carrier frequency of 10 GHz. Only 10% of it is utilized for transmission. How many telephonic channels can be transmitted simultaneously if each channel requires a bandwidth of 5 kHz?
2 x 106
2 x 105
2 x 104
2 x 105