The human heart is which type?

The shortest distance between the lines $r=3i+5j+7k+\lambda(i+2j+k)$ and $r=-i-j-k+\mu(7i-6j+k)$ is

Which one of the taxonomic aids can give comprehensive account of complete compiled information of any one genus or family at a particular time?

Which of the following acts as both an oxidizing agent and a reducing agent?

Power supplied to a particle of mass $2 \ kg$ varies with time as $P = \frac{3t^2}{2} \ W$. Here,$t$ is in $s$. If the velocity of the particle at $t = 0$ is $v = 0$,the velocity of the particle at time $t = 2 \ s$ will be ............. $m/s$.

The standard reduction potentials of $Zn^{2+}|Zn$,$Cu^{2+}|Cu$ and $Ag^{+}|Ag$ are respectively $-0.76 \ V$,$0.34 \ V$ and $0.8 \ V$. The following cells were constructed:
$(1)$ $Zn|Zn^{2+}||Cu^{2+}|Cu$
$(2)$ $Zn|Zn^{2+}||Ag^{+}|Ag$
$(3)$ $Cu|Cu^{2+}||Ag^{+}|Ag$
What is the correct order of $E_{cell}^{\circ}$ of these cells?