Biolistics (gene gun) is suitable for

If the product of the roots of the equation $(a + 1)x^2 + (2a + 3)x + (3a + 4) = 0$ is $2$,then the sum of the roots is:

If the radius of a star is $R$ and it acts as a black body,what would be the temperature of the star,in which the rate of energy production is $Q$? ( $\sigma$ stands for Stefan's constant.)

The magnifying power of a simple microscope is (when the final image is formed at $D = 25 \ cm$ from the eye):

$A$ photon collides with a stationary hydrogen atom in the ground state inelastically. The energy of the colliding photon is $10.2 \, eV$. After a time interval of the order of a microsecond,another photon collides with the same hydrogen atom inelastically with an energy of $15 \, eV$. What will be observed by the detector?

$SiCl_4$ on hydrolysis forms '$X$' and $HCl$. Compound '$X$' loses water at $1000^\circ C$ and gives '$Y$'. Compounds '$X$' and '$Y$' respectively are: