When current in a coil changes from $5\,A$ to $2\,A$ in $0.1\,s$,an average voltage of $50\,V$ is produced. The self-inductance of the coil is $............H$.

$A$ coil of wire of radius $r$ has $600$ turns and a self-inductance of $108 \ mH$. The self-inductance of a coil with the same radius and $500$ turns is: (in $mH$)

The probabilities of $A$ and $B$ dying in a year are $p$ and $q$ respectively. What is the probability that only one of them will be alive at the end of the year?

Which of the following is a bactericidal antibiotic?

Water is conveyed through a uniform tube of $8 \text{ cm}$ in diameter and $3140 \text{ m}$ in length at the rate of $2 \times 10^{-3} \text{ m}^3/\text{s}$. The pressure required to maintain the flow is (Viscosity of water $= 10^{-3} \text{ SI units}$):

Which of the following statements are true about acceleration due to gravity $(g)$ of the earth (where $r$ is distance from the centre of the earth and $R$ is the radius of the earth)?
$(a)$ $g$ decreases in moving away from the centre,if $r > R$.
$(b)$ $g$ decreases in moving away from the centre,if $r < R$.
$(c)$ $g$ is zero at the centre of the earth.
$(d)$ $g$ at the equator decreases,if the earth stops rotating about its axis.