select the correct answer.\na beam of electrons moves at right angles to a magnetic field of 4.5×10⁻² tesla…

select the correct answer.\na beam of electrons moves at right angles to a magnetic field of 4.5×10⁻² tesla. if the electrons have a velocity of 6.5×10⁶ meters/second, what is the force acting on the electrons? the value of q = -1.6×10⁻¹⁹ coulombs.\n\na. -2.9×10⁶ n\nb. -3.9×10⁻¹⁴ n\nc. -4.9×10⁻¹⁴ n\nd. -6.5×10⁻¹³ n

select the correct answer.\na beam of electrons moves at right angles to a magnetic field of 4.5×10⁻² tesla. if the electrons have a velocity of 6.5×10⁶ meters/second, what is the force acting on the electrons? the value of q = -1.6×10⁻¹⁹ coulombs.\n\na. -2.9×10⁶ n\nb. -3.9×10⁻¹⁴ n\nc. -4.9×10⁻¹⁴ n\nd. -6.5×10⁻¹³ n

Answer

Explanation:

Step1: Recall the formula for magnetic force

$F = qvB\sin\theta$ Since the electrons move at right - angles to the magnetic field, $\theta = 90^{\circ}$ and $\sin\theta=\sin90^{\circ}=1$.

Step2: Substitute the given values

$q=- 1.6\times10^{-19}\text{ C}$, $v = 6.5\times10^{6}\text{ m/s}$, $B = 4.5\times10^{-2}\text{ T}$ $F=(-1.6\times 10^{-19})\times(6.5\times 10^{6})\times(4.5\times 10^{-2})\times1$ First, multiply the numerical values: $1.6\times6.5\times4.5=1.6\times29.25 = 46.8$ Then, multiply the powers of 10: $10^{-19}\times10^{6}\times10^{-2}=10^{-19 + 6-2}=10^{-15}$ $F=-46.8\times10^{-15}\text{ N}=-4.68\times10^{-14}\text{ N}\approx - 4.9\times10^{-14}\text{ N}$

Answer:

C. $-4.9\times 10^{-14}\text{ N}$