$A$ particle is performing $SHM$ starting from the extreme position. The graphical representation shows that, between displacement and acceleration, there is a phase difference of:

The proposition $(p$ $\Rightarrow \;\sim p) \wedge (\sim p$ $\Rightarrow p)$ is a

$10\, g$ of ice at $-20^{\circ}C$ is dropped into a calorimeter containing $10\, g$ of water at $10^{\circ}C$. The specific heat of water is twice that of ice. When equilibrium is reached,the calorimeter will contain:

When a non-volatile solute is added to a solvent,the vapor pressure decreases by $10 \ mm$. The mole fraction of the solute is $0.2$. If the vapor pressure decreases by $20 \ mm$,what will be the mole fraction of the solvent?

The steps of a plant breeding program are given below. Arrange them in the correct sequence.
$(a)$ Cross-hybridization among the selected parents
$(b)$ Testing,release,and commercialization of new cultivars
$(c)$ Collection of variability
$(d)$ Selection and testing of superior recombinants
$(e)$ Evaluation and selection of parents

If the axes are rotated through an angle $\alpha$,then the number of values of $\alpha$ such that the transformed equation of $x^2+y^2+2x+2y-5=0$ contains no linear terms is