The ratio of wavelengths for transition of electrons from $$2^{\text {nd }}$$ orbit to $$1^{\text {st }}$$ orbit of Helium $$\left(\mathrm{He}^{++}\right)$$ and Lithium $$\left(\mathrm{Li}^{++1}\right)$$ is (Atomic number of Helium $$=2$$, Atomic number of Lithium $$=3$$ )
A body at rest falls through a height 'h' with velocity 'V'. If it has to fall down further for its velocity to become three times, the distance travelled in that interval is
A bomb is dropped by an aeroplane flying horizontally with a velocity $$200 \mathrm{~km} / \mathrm{hr}$$ and at a height of $$980 \mathrm{~m}$$. At the time of dropping a bomb, the distance of the aeroplane from the target on the ground to hit directly is $$\left(g=9.8 \mathrm{~m} / \mathrm{s}^2\right)$$
A cricket player hit a ball like a projectile but the fielder caught the ball after 2 second. The maximum height reached by a ball is (g = 10 m/s2)