The complete hydrolysis of $ICl , ClF _3$ and $BrF _5$, respectively, gives

$A$ radioactive nucleus $A$ with a half-life $T$ decays into a nucleus $B$. At $t = 0$,there is no nucleus $B$. At some time $t$,the ratio of the number of $B$ nuclei to that of $A$ nuclei is $0.3$. Then,$t$ is given by:

Let $A = \{ x: x \in R, |x| < 1 \}$ and $B = \{ x: x \in R, |x - 1| \ge 1 \}$. If $A \cup B = R - D$,then the set $D$ is:

The resolving limit of a healthy human eye is about

Among the following ions,which one has the highest paramagnetism?

The circuit shown contains a $12 \, V$ battery,a $4 \, \Omega$ resistor,and two branches in parallel,each containing an ideal diode and a resistor. Branch $1$ has diode $D_1$ and a $3 \, \Omega$ resistor,while branch $2$ has diode $D_2$ and a $2 \, \Omega$ resistor. Determine the total current flowing in the circuit. (in $, A$)