MCQ
A vector is added to an equal and opposite vector of similar nature, forms a ........
- AUnit vector
- BPosition vector
- ✓Null vector
- DDisplacement vector
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[Given: Wien's constant as $2.9 \times 10^{-3} \mathrm{~m}-\mathrm{K}$ and $\frac{\mathrm{hc}}{\mathrm{e}}=1.24 \times 10^{-6} \mathrm{~V}-\mathrm{m}$ ]
| List-$I$ | List-$II$ |
| ($P$) $2000 \mathrm{~K}$ | ($1$) The radiation at peak wavelength can lead to emission of photoelectrons from a metal of work function $4 \mathrm{eV}$ |
| ($Q$) $3000 \mathrm{~K}$ | ($2$) The radiation at peak wavelength is visible to human eye. |
| ($R$) $5000 \mathrm{~K}$ | ($3$) The radiation at peak emission wavelength will result in the widest central maximum of a single slit diffraction. |
| ($S$) $10000 \mathrm{~K}$ | ($4$) The power emitted per unit area is $1 / 16$ of that emitted by a blackbody at temperature $6000 \mathrm{~K}$. |
| ($5$) The radiation at peak emission wavelength can be used to image human bones. |
$\vec E = 2{E_0}\,\hat i\,\cos\, kz\,\cos\, \omega t$
Its magnetic field $\vec B$ is then given by
