The standard e.m.f. of a cell,involving one electron change is found to be $0.591 \ V$ at $25 \ ^oC$. The equilibrium constant of the reaction is ($F = 96,500 \ C \ mol^{-1}$; $R = 8.314 \ JK^{-1} \ mol^{-1}$)

The binding energy per nucleon versus mass number curve for nuclei is shown in the figure. $W, X, Y$ and $Z$ are four nuclei indicated on the curve. The process that would release energy is

What is the time (in $sec$) required for depositing all the silver present in $125 \ mL$ of $1 \ M \ AgNO_3$ solution by passing a current of $241.25 \ A$? $(1 \ F = 96500 \ C)$

Total emf produced in a thermocouple does not depend on

Read the following five statements $(1-5)$ carefully and answer the question that follows.
$(1)$ In $Equisetum$,the female gametophyte is retained on the parent sporophyte.
$(2)$ In $Ginkgo$,the male gametophyte is not independent.
$(3)$ The sporophyte of $Polytrichum$ is more developed than that of $Riccia$.
$(4)$ Sexual reproduction in $Volvox$ is isogamous.
$(5)$ Spores of slime molds lack a cell wall.
How many of the above statements are correct?

$A$ smooth sphere $A$ is moving on a frictionless horizontal plane with an angular velocity $\omega$ and a linear velocity $v$ of its center of mass. It undergoes an elastic head-on collision with an identical sphere $B$ which is at rest. If there is no friction anywhere,then after the collision,their angular speeds are $\omega_A$ and $\omega_B$ respectively. Then: