The power dissipated in the circuit shown in the figure $$40 \mathrm{~W}$$. The value of $$R$$ is.
In a YDSE, the light of wavelength $$\lambda=5000\mathop A\limits^o $$ is used, which emerges in phase from two slits at $$a$$ distance $$d=3 \times 10^{-7} \mathrm{~m}$$ apart. A transparent sheet of thickness $$t=1.5 \times 10^{-7} \mathrm{~m}$$ and refractive index $$\mu=1.25$$ is placed over one of the slits. What is the new angular position of the central maxima of the interference pattern, from the centre of the screen? Find the value of $$y$$.
The electric and the magnetic field associated with an E.M. wave, propagating along the $$\mathrm{Z}$$-axis can be represented by
An electron of mass $$m$$ and charge $$e$$ initially at rest gets accelerated by a constant field $$2 E$$. The rate of change of de-Broglie wavelength of this electron at time $$t$$ ignoring relativistic effects is