$A$ wire elongates by $l \, mm$ when a load $W$ is hanged from it. If the wire goes over a pulley and two weights $W$ each are hung at the two ends,the elongation of the wire will be (in $mm$):

What is a species?

An object of mass $0.2 \, kg$ executes simple harmonic motion along the $X$-axis with a frequency of $\frac{25}{\pi} \, Hz$. At the position $x = 0.04 \, m$,the object has a kinetic energy of $0.5 \, J$ and a potential energy of $0.4 \, J$. The amplitude of oscillation in meters is equal to:

In the $NO_3^-$ ion,what are the number of bond pairs and lone pairs of electrons on the $N$ atom,respectively?

If all interior angles of a quadrilateral are in $AP$ and the common difference is $10^{\circ}$,then find the smallest angle in degrees.

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 ............... $\Omega$.