Question

In an npn transistor, the collector current is 24 mA. If 80% of electrons reach collector, its base current in mA is ______.

Options

• 36

• 1.08 s

• 0.54 s

• 8.64 s

Answer 1

In an npn transistor, the collector current is 24 mA. If 80% of electrons reach collector, its base current in mA is 6.

Explanation:

Given, `"I"_"C" = 80/100 xx"I"_"E"`

`therefore 24 = 80/100 xx"I"_"E"`

`therefore "I"_"E" = 24 xx1/0.8`

= 30mA

By using ` "I"_"E" = "I"_"B" + "I"_"c" => "I"_"B" = 30 - 24 `= 6 mA