Gymnosperms lack true fruits because .........

The uncertainties in the velocities of two particles $A$ and $B$ are $0.05 \ m/s$ and $0.02 \ m/s$ respectively. The mass of $B$ is five times that of mass $A$. What is the ratio of uncertainties $\left(\frac{\Delta x_A}{\Delta x_B}\right)$ in their positions?

$A$ body cools from $60\,^oC$ to $50\,^oC$ in $10\,minutes$. If the room temperature is $25\,^oC$ and assuming Newton's law of cooling to hold good,the temperature of the body at the end of the next $10\,minutes$ will be ......... $^oC$.

Which statement is false for the balanced equation given below?
$CS_2 + 3O_2 \to 2SO_2 + CO_2$

The surface of a metal is illuminated with light of $400\, nm$. The maximum kinetic energy of the ejected photoelectrons was found to be $1.68\, eV$. The work function of the metal is.......$eV$ $(hc = 1240\, eV\, nm)$.

Two conducting circular loops of radii $R_1$ and $R_2$ are placed in the same plane with their centres coinciding. If $R_1 >> R_2$,the mutual inductance $M$ between them will be directly proportional to