The equation of the line joining the centres of the circles belonging to the coaxial system of circles $4x^2 + 4y^2 - 12x + 6y - 3 + \lambda(x + 2y - 6) = 0$ is

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

If $\cos \theta - 4 \sin \theta = 1$,then $\sin \theta + 4 \cos \theta$ is equal to

An atomic power nuclear reactor can deliver $300 \, MW$. The energy released due to the fission of each nucleus of uranium atom $U^{238}$ is $170 \, MeV$. The number of uranium atoms fissioned per hour will be:

$A$ bag contains $6$ white and $4$ black balls. Two balls are drawn at random. The probability that they are of the same colour is:

Read the following five statements and answer the question.
$(a)$ In $Equisetum$ the female gametophyte is retained on the parent sporophyte.
$(b)$ In $Ginkgo$ male gametophyte is not independent.
$(c)$ The sporophyte in $Riccia$ is more developed than that in $Polytrichum$.
$(d)$ Sexual reproduction in $Volvox$ is isogamous.
$(e)$ The spores of slime molds lack cell walls.
How many of the above statements are correct?