The gas used in the hydrogenation of vegetable oils in the presence of nickel as catalyst is

The shield-shaped cotyledon seen in monocot seeds is known as:

$A$ man wants to reach a certain destination. One-sixth of the total distance is muddy while half the distance is tar road. For the remaining distance,he takes a boat. His speed of travelling in mud,in water,and on tar road is in the ratio $3:4:5$. The ratio of the durations he requires to cross the patch of mud,stream,and tar road is

Cardiac muscle fibers differ from skeletal muscle fibers in that they are -

Let $A$ and $B$ be two symmetric matrices of the same order. Then,the matrix $AB - BA$ is

$A$ body is executing simple harmonic motion. At a displacement $x$ its potential energy is $E_1$ and at a displacement $y$ its potential energy is $E_2$. The potential energy $(E)$ at displacement $(x+y)$ is