The de-Broglie wavelength of a particle moving with a velocity $2.25 \times 10^8 \, m/s$ is equal to the wavelength of a photon. The ratio of the kinetic energy of the particle to the energy of the photon is (velocity of light is $3 \times 10^8 \, m/s$):- (in $/8$)

$A$ scion is grafted to a stock. The quality of fruits produced will be determined by the genotype of

Three rods $AB$,$BC$,and $BD$ made of the same material and having the same cross-section have been joined as shown in the figure. The ends $A$,$C$,and $D$ are held at temperatures of $20^{\circ}C$,$80^{\circ}C$,and $80^{\circ}C$ respectively. If each rod is of the same length,then the temperature at the junction $B$ of the three rods is: (in $^{\circ}C$)

$A$ short magnetic needle is pivoted in a uniform magnetic field of induction $1 ~T$. Now,simultaneously another magnetic field of induction $\sqrt{3} ~T$ is applied at right angles to the first field; the needle deflects through an angle $\theta$ whose value is (in $^{\circ}$)

Which of the following is the correct electronic configuration of a neutral $Carbon$ atom in its ground state?

Which of the following is not correctly matched?