Which of the following is $NOT$ produced by the reaction of ethanol with $H_2SO_4$?

Which of the following plants is known for its hallucinogenic properties?

If $200 \text{ MeV}$ of energy is released in the fission of one nucleus of ${ }_{92}^{235} \text{U}$,then the number of nuclei that must undergo fission to release an energy of $1000 \text{ J}$ is

$A$ particle starts from a point $P$ at a distance of $A/2$ from the mean position $O$ and travels towards the left as shown in the figure. If the time period of $SHM$ executed about $O$ is $T$ and the amplitude is $A$,then the equation of motion of the particle is:

Four particles $A, B, C$ and $D$ of equal mass $m$ are placed at the four corners of a square. They move with equal uniform speed $v$ towards the intersection of the diagonals. After the collision,particle $A$ comes to rest,particle $B$ traces its path back with the same speed $v$,and particles $C$ and $D$ move with equal speeds $v'$. What is the velocity of particle $C$ after the collision?

If the sum of two of the roots of $x^3+p x^2-q x+r=0$ is zero,then $p q$ is equal to