$A$ double convex lens,made of a material of refractive index $\mu_1$,is placed inside two liquids of refractive indices $\mu_2$ and $\mu_3$,as shown. Given $\mu_2 > \mu_1 > \mu_3$. $A$ wide,parallel beam of light is incident on the lens from the left. The lens will give rise to

Two coins $A$ and $B$ are kept in an urn. When coin $A$ is flipped,the probability of getting a Head is $1/4$,while for coin $B$ it is $3/4$. One coin is randomly chosen from this bag and tossed twice,and it falls heads on both occasions. The probability that it is coin $A$ is:

The work done by a force $\vec F = (-6x^3 \hat i) \, N$,in displacing a particle from $x = 4 \, m$ to $x = -2 \, m$ is ................ $J$.

Muddy water can be purified through coagulation using

Which property of hydrogen distinguishes it from alkali metals?