Here's a plot of Ic, with Vcc swept from 0 to 10V.
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Here's a plot of Ic, with Vcc swept from 0 to 10V.
Yes, you raise some good points here. The statement that beta is 50 would need to be assumed to be in the linear region. In a another thread, I once posted a derivation of beta (needed for a current control model) assuming the Ebers-Moll model which is a voltage control model that displays many important low-frequency features of the transistor. (see attached PDF).But back in the world of real transistors it's much more complex. After much thinking on the issue, it occurs to me that the question set can't be solved. For a start, beta won't be 50, it will be (assuming Vce(sat)=200mV) 9.8mA/230uA=42.6. I guess the assumption is that beta is 50 when there's a bit more headroom available from a higher Vcc supply, but that would imply a higher Vce, and beta is a function of Vce, as can be seen by the "constant" current section of Ron H's graph, which isn't that constant at all because the slope is non-zero.