Statement I: Intensity of X-rays can be controlled by adjusting the filament current and voltage.
Statement I!: The intensity of X-rays does not depend on number of photons emitted per second from the target.
Intensity of X-rays (1) is proportional to the filament current and also to the square of the voltage. It is well known that intensity of X-rays depends on the number of photons emitted per second from target.