How many bridging oxygen atoms are present in $P_4O_{10}$?

The current in an $AC$ circuit is given by $i = i_1 \sin \omega t + i_2 \cos \omega t$. Its $r.m.s.$ value is:

Bordeaux mixture was discovered by

Two equal resistances when connected in series to a battery,consume electric power of $60 \ W$. If these resistances are now connected in parallel combination to the same battery,the electric power consumed will be............. $W$

After $280\,days$,the activity of a radioactive sample is $6000\,dps$. The activity reduces to $3000\,dps$ after another $140\,days$. The initial activity of the sample in $dps$ is

Which of the following compounds will be most easily attacked by an electrophile?