The silicate having one monovalent corner oxygen atom in each tetrahedron unit is:

In the circuit shown,the reading of the Ammeter is doubled after the switch is closed. Each resistor has a resistance $= 1\,\Omega$ and the ideal cell has an $e.m.f. = 10\,V$. Then,the Ammeter has a coil resistance equal to .............. $\Omega$.

Which of the following represents the complexity of body organization?

$A$ fireman of mass $60 \, kg$ slides down a pole. He is pressing the pole with a force of $600 \, N$. The coefficient of friction between the hands and the pole is $0.5$. With what acceleration will the fireman slide down (in $, m/s^2$)? (Take $g = 10 \, m/s^2$)

In the electrolytic extraction of $Al$,molten cryolite $(Na_3AlF_6)$ is used because it .......

Which one of the following pairs of reactants does not form oxygen when they react with each other?