Advertisements
Advertisements
प्रश्न
A radio can tune in to any station in the 7.5 MHz to 12 MHz band. What is the corresponding wavelength band?
उत्तर
A radio can tune to minimum frequency, v1 = 7.5 MHz = 7.5 × 106 Hz
Maximum frequency, v2 = 12 MHz = 12 × 106 Hz
Speed of light, c = 3 × 108 m/s
Corresponding wavelength for v1 can be calculated as:
`lambda_1 = "c"/"v"_1`
= `(3 xx 10^8)/(7.5 xx 10^6)`
= 40 m
Corresponding wavelength for v2 can be calculated as:
`lambda_2 = "c"/"v"_2`
= `(3 xx 10^8)/(12 xx 10^6)`
= 25 m
Thus, the wavelength band of the radio is 40 m to 25 m.
APPEARS IN
संबंधित प्रश्न
Use the formula λm T= 0.29 cm K to obtain the characteristic temperature ranges for different parts of the electromagnetic spectrum. What do the numbers that you obtain tell you?
Name the phenomenon which shows the quantum nature of electromagnetic radiation.
What is the range of the wavelength of the following electromagnetic waves?
(a) Visible.
What is the range of the wavelength of the following electromagnetic waves?
(a) Micro waves .
Name two electromagnetic waves of frequency smaller than that of violet light. State one use of each.
Can X-rays be used for photoelectric effect?
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
X-ray from a Coolidge tube is incident on a thin aluminium foil. The intensity of the X-ray transmitted by the foil is found to be I0. The heating current is increased to increase the temperature of the filament. The intensity of the X-ray transmitted by the foil will be
(a) zero
(b) < I0
(c) I0
(d) > I0
Heat at the rate of 200 W is produced in an X-ray tube operating at 20 kV. Find the current in the circuit. Assume that only a small fraction of the kinetic energy of electrons is converted into X-rays.
If the operating potential in an X-ray tube is increased by 1%, by what percentage does the cutoff wavelength decrease?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Two waves A and B have wavelength 0.01 Å and 9000 Å respectively.
Name the two waves. compare the speeds of these waves when they travel in vacuum.
| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
(d) Name one source of each of the radiation of electromagnetic spectrum.
(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
Name the radiation of the electromagnetic spectrum which is used for the following:
To photograph internal parts of the human body and Give the frequency range
Choose the correct option.
The EM wave emitted by the Sun and responsible for heating the Earth’s atmosphere due to greenhouse effect is
Solve the numerical problem.
The speed of light is 3 × 108 m/s. Calculate the frequency of red light of a wavelength of 6.5 × 10−7 m.
A car is moving towards a high cliff. The car driver sounds a horn of frequency f. The reflected sound heard by the driver has a frequency 2f. If v be the velocity of sound, then the velocity of the car, in the same velocity units, will be:
Microwaves are electromagnetic waves with frequency in the range of.
Following QN ∴ 14, the radiation force on the roof will be
Radio waves of constant amplitude can be generated with.
The magnetic field of a beam emerging from a filter facing a floodlight is given by B0 = 12 × 10–8 sin (1.20 × 107z – 3.60 × 1015t) T. What is the average intensity of the beam?
