$3.011 \times 10^{22}$ atoms of an element weigh $1.15 \ g$. The atomic mass of the element is:

What is the major product of the following reaction?

$A$ galvanometer of resistance $50\,\Omega$ is connected to a battery of $3\,V$ along with a resistance of $2950\,\Omega$ in series. $A$ full-scale deflection of $30$ divisions is obtained in the galvanometer. In order to reduce this deflection to $20$ divisions,the resistance in series should be.......$\Omega$.

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

The mass of oxygen gas occupying a volume of $11.2 \text{ litres}$ at a temperature $27^{\circ}C$ and a pressure of $760 \text{ mm}$ of mercury in kilograms is $[$Molecular weight of oxygen $= 32]$

$A$ block of $200 \ g$ mass moves with a uniform speed in a horizontal circular groove,with vertical side walls of radius $20 \ cm$. If the block takes $40 \ s$ to complete one round,the normal force by the side walls of the groove is: