Chapter 23 - Magnetic Flux and Faraday's Law of Induction - Problems and Conceptual Exercises - Page 831: 36

$B=0.30T$

Induced emf of a moving bar is equal to $$\mathcal{E}=Blv$$ Solving for field strength $B$ yields $$B=\frac{\mathcal{E}}{lv}$$ Substituting known values of $\mathcal{E}=0.45V$, $l=0.76m$, and $v=2.0m/s$ yields a magnetic field strength of $$B=\frac{0.45V}{(0.76m)(2.0m/s)}=0.30T$$