A thin plano-convex lens of focal length $$f$$ is split into two halves one of the halves is shifted along the optical axis. The separation between object and image formed by one of the half-lenses is 2.4 and the magnification of same lens is 2. If $$f$$ and $$d$$ be the focal length of the lens and separation between the two halves respectively then
The potential energy for a force field $$\mathbf{F}$$ is given by $$u(x, y)=\cos (x+y)$$. The force acting on a particle at position given by co-ordinates $$(0, \pi / 6)$$ is
A direct current of $$10 \mathrm{~A}$$ is superimposed on an alternating current $$i=10 \sin \omega t$$ flowing through the wire. The effective value of the resulting current will be.
The $$x$$-$$t$$ graph of a particle performing simple harmonic motion is shown in the figure. The acceleration of the particle at $$t=2. \mathrm{~s}$$ is