The major product of the following reaction is :

Which one of the following sets correctly represents the increase in the paramagnetic property of the ions?

Two waves $Y_{1} = 0.25 \sin(316 t)$ and $Y_{2} = 0.25 \sin(310 t)$ are propagating along the same direction. The number of beats produced per second is:

Three metal rods of the same material and identical in all respects are joined as shown in the figure. The temperatures at the ends are maintained as indicated. Assuming no loss of heat from the curved surfaces of the rods,the temperature at the junction $X$ would be ....... $^oC$

$A$ convex lens is made up of three different materials as shown in the figure. For a point object placed on its axis,the number of images formed are

The horizontal range is four times the maximum height attained by a projectile. The angle of projection is ......... $^o$