What is the product formed when benzylamine reacts with nitrous acid?

If $x = \log_{5}(1000)$ and $y = \log_{7}(2058)$,then:

One litre of oxygen at a pressure of $1\, atm$ and two litres of nitrogen at a pressure of $0.5\, atm$ are introduced into a vessel of volume $1\, L$. If there is no change in temperature,the final pressure of the mixture of gas (in $atm$) is

The number of roots of the equation $(81)^{\sin ^2 x} + (81)^{\cos ^2 x} = 30$ in the interval $[0, \pi]$ is equal to

When a train stops suddenly,passengers in the running train feel an instant jerk in the forward direction because

In the adjacent circuit,a voltmeter of internal resistance $R$,when connected across $B$ and $C$,reads $\frac{100}{3} \text{ V}$. Neglecting the internal resistance of the battery,the value of $R$ is