If the length of the tangent from $(h, k)$ to the circle $x^2+y^2=16$ is twice the length of the tangent from the same point to the circle $x^2+y^2+2x+2y=0$,then

Two vibrating tuning forks produce progressive waves given by $Y_1 = 4 \sin(500\pi t)$ and $Y_2 = 2 \sin(506\pi t)$. The number of beats produced per minute is:

The binding energy per nucleon of $^{16}O$ is $7.97 \, MeV$ and that of $^{17}O$ is $7.75 \, MeV$. The energy (in $MeV$) required to remove a neutron from $^{17}O$ is:

Which mixture forms a buffer when dissolved in $1 \, L$ of water?

If $y=a e^x+b e^{-x}+c$,where $a, b, c$ are parameters,then $y^{\prime \prime \prime}$ is equal to

The rate of steady volume flow of water through a capillary tube of length $l$ and radius $r$,under a pressure difference of $p$ is $V$. This tube is connected with another tube of the same length but half the radius,in series. Then,the rate of steady volume flow through them is (The pressure difference across the combination is $p$.)