The refractive index of the material of the prism for violet colour is $1.69$ and that for red is $1.65$. If the refractive index for mean colour is $1.66$,what is the dispersive power of the material of the prism?

$A$ uniform rope of length $L$ and mass $m_1$ hangs vertically from a rigid support. $A$ block of mass $m_2$ is attached to the free end of the rope. $A$ transverse pulse of wavelength $\lambda_1$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is $\lambda_2$. The ratio $\lambda_2/\lambda_1$ is

$(x^2+y^2) dy = xy dx$. If $y(x_0) = e$ and $y(1) = 1$,then the value of $x_0$ is equal to

Which one of the following structures between two adjacent cells is an effective transport pathway?

$A$ body weighs $72 \ N$ on the surface of the earth. What is the gravitational force (in $N$) on it,at a height equal to half the radius of the earth?