If $10000\, V$ is applied across an $X$-ray tube, what will be the ratio of the de-Broglie wavelength of the incident electrons to the shortest wavelength of the $X$-rays produced? (Given: $\frac{e}{m}$ for an electron is $1.8 \times 10^{11}\, C\, kg^{-1}$)

The centre of a circle is $(2, -3)$ and the circumference is $10\pi$. Then the equation of the circle is

Extraction of zinc from zinc blende is achieved by:

Which of the following substances releases nitrogen gas upon thermal decomposition?

If $\int(1-\cos x) \operatorname{cosec}^2 x \, dx = f(x) + c$, then $f(x)$ is equal to

$A$ square loop of area $25 \, cm^2$ has a resistance of $10 \, \Omega$. This loop is placed in a uniform magnetic field of magnitude $40 \, T$. The plane of the loop is perpendicular to the magnetic field. The work done in pulling the loop out of the magnetic field slowly and uniformly in one second will be: