Consider the situation shown in figure, A spring of spring constant $400\,N / m$ is attached at one end to a wedge fixed rigidly with the horizontal part. A $40\,g$ mass is released from rest while situated at a height $5\,cm$ the curved track. The minimum deformation in the spring is nearly equal to (take $g =10\,m / s ^2$ )

Stimulation of a muscle fiber by a motor neuron occurs at:

Which of the following compounds does not exhibit mutarotation?

The value of $\lambda$ with $|\lambda| < 16$ such that $2 x^2 - 10 x y + 12 y^2 + 5 x + \lambda y - 3 = 0$ represents a pair of straight lines,is

Electrons ejected from the surface of a metal,when light of certain frequency is incident on it,are stopped fully by a retarding potential of $3 \ V$. Photoelectric effect in this metallic surface begins at a frequency $6 \times 10^{14} \ s^{-1}$. The frequency of the incident light in $s^{-1}$ is : [Planck's constant $= 6.4 \times 10^{-34} \ J \ s$,charge on the electron $= 1.6 \times 10^{-19} \ C$]

In an optical fibre,the core and cladding are made with materials of refractive indices $1.5$ and $1.414$ respectively. To observe total internal reflection,what will be the range of the incident angle with the axis of the optical fibre?