Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs.
$(a)$ $21 \; cm$ (wavelength emitted by atomic hydrogen in interstellar space).
$(b)$ $1057 \; MHz$ (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift).
$(c)$ $2.7 \; K$ (temperature associated with the isotropic radiation filling all space; thought to be a relic of the 'big-bang' origin of the universe).
$(d)$ $5890 \; \mathring{A} - 5896 \; \mathring{A}$ (double lines of sodium).
$(e)$ $14.4 \; keV$ (energy of a particular transition in $^{57}Fe$ nucleus associated with a famous high-resolution spectroscopic method, Mossbauer spectroscopy).
$(a)$ $21 \; cm$ (wavelength emitted by atomic hydrogen in interstellar space).
$(b)$ $1057 \; MHz$ (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift).
$(c)$ $2.7 \; K$ (temperature associated with the isotropic radiation filling all space; thought to be a relic of the 'big-bang' origin of the universe).
$(d)$ $5890 \; \mathring{A} - 5896 \; \mathring{A}$ (double lines of sodium).
$(e)$ $14.4 \; keV$ (energy of a particular transition in $^{57}Fe$ nucleus associated with a famous high-resolution spectroscopic method, Mossbauer spectroscopy).
$(a)$ Radio waves; it belongs to the short wavelength end of the electromagnetic spectrum.
$(b)$ Radio waves; it belongs to the short wavelength end.
$(c)$ Temperature, $T = 2.7 \; K$. According to Wien's displacement law, the wavelength $\lambda_{m}$ corresponding to maximum intensity is given by $\lambda_{m} = \frac{b}{T} \approx \frac{0.29 \; cm \cdot K}{2.7 \; K} \approx 0.11 \; cm$. This wavelength corresponds to microwaves.
$(d)$ This is the yellow light of the visible spectrum.
$(e)$ Transition energy is given by $E = h\nu$. For $E = 14.4 \; keV = 14.4 \times 10^3 \times 1.6 \times 10^{-19} \; J$, the frequency $\nu = \frac{E}{h} \approx 3.5 \times 10^{18} \; Hz$. This corresponds to $X$-rays.
$(b)$ Radio waves; it belongs to the short wavelength end.
$(c)$ Temperature, $T = 2.7 \; K$. According to Wien's displacement law, the wavelength $\lambda_{m}$ corresponding to maximum intensity is given by $\lambda_{m} = \frac{b}{T} \approx \frac{0.29 \; cm \cdot K}{2.7 \; K} \approx 0.11 \; cm$. This wavelength corresponds to microwaves.
$(d)$ This is the yellow light of the visible spectrum.
$(e)$ Transition energy is given by $E = h\nu$. For $E = 14.4 \; keV = 14.4 \times 10^3 \times 1.6 \times 10^{-19} \; J$, the frequency $\nu = \frac{E}{h} \approx 3.5 \times 10^{18} \; Hz$. This corresponds to $X$-rays.
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The frequencies of $\gamma$-rays,$X$-rays,and ultraviolet radiations are $B, A,$ and $C$ respectively. Which of the following relations is correct?
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View SolutionMatch List-$I$ with List-$II$.
List-$I$ List-$II$ $A$. Microwaves $I$. Physiotherapy $B$. $UV$ rays $II$. Treatment of cancer $C$. Infra-red rays $III$. Lasik eye surgery $D$. $X$-rays $IV$. Aircraft navigation
Choose the correct answer from the options given below:
| List-$I$ | List-$II$ |
|---|---|
| $A$. Microwaves | $I$. Physiotherapy |
| $B$. $UV$ rays | $II$. Treatment of cancer |
| $C$. Infra-red rays | $III$. Lasik eye surgery |
| $D$. $X$-rays | $IV$. Aircraft navigation |
Choose the correct answer from the options given below:
Match the List-$I$ (Phenomenon associated with electromagnetic radiation) with List-$II$ (Part of electromagnetic spectrum) and select the correct code from the choices given below:
List-$I$ List-$II$ $I$. Doublet of sodium $A$. Visible radiation $II$. Wavelength corresponding to temperature associated with the isotropic radiation filling all space $B$. Microwave $III$. Wavelength emitted by atomic hydrogen in interstellar space $C$. Short radio wave $IV$. Wavelength of radiation arising from two close energy levels in hydrogen (Lamb shift) $D$. $X$-rays
| List-$I$ | List-$II$ |
| $I$. Doublet of sodium | $A$. Visible radiation |
| $II$. Wavelength corresponding to temperature associated with the isotropic radiation filling all space | $B$. Microwave |
| $III$. Wavelength emitted by atomic hydrogen in interstellar space | $C$. Short radio wave |
| $IV$. Wavelength of radiation arising from two close energy levels in hydrogen (Lamb shift) | $D$. $X$-rays |
Match List-$I$ with List-$II$.
List-$I$ List-$II$ $(a)$ $10\, km$ height over earth's surface $(i)$ Thermosphere $(b)$ $70\, km$ height over earth's surface $(ii)$ Mesosphere $(c)$ $180\, km$ height over earth's surface $(iii)$ Stratosphere $(d)$ $270\, km$ height over earth's surface $(iv)$ Troposphere
| List-$I$ | List-$II$ |
| $(a)$ $10\, km$ height over earth's surface | $(i)$ Thermosphere |
| $(b)$ $70\, km$ height over earth's surface | $(ii)$ Mesosphere |
| $(c)$ $180\, km$ height over earth's surface | $(iii)$ Stratosphere |
| $(d)$ $270\, km$ height over earth's surface | $(iv)$ Troposphere |
The waves used in telecommunication are
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