The neutral base width of a bipolar transistor biased in the active region is 0.4 μm, the maximum electron concentration and the diffusion constant in the base are 1015/cm3 and 25 cm2/sec respectively. Assuming almost negligible recombination in the base, the collector current density is
1
50 A/cm2
2
100 A/cm2
3
25 A/cm2
4
75 A/cm2