An op-amp uses differential amplifier at the input stage. Base currents of the two emitter coupled transistors of the differential amplifier are 20 μA and 22 μA. What is the input bias current for the op-amp?

Question

Question

This question was previously asked in

BSPHCL JE Electrical 2019 Official Paper: Batch 2 (Held on 31 Jan 2019)

Attempt Online

Answer 1

The correct answer is option 2):(21 μA)

Concept:

Input Bias Current = \(\frac{{{{\rm{I}}_{b1}} + {{\rm{I}}_{b2}}}}{2}\)

Where I_b1_,I_b2 are the base current in A

Calculation:

I_b1 = 20 μA

Ib2 = 22 μA

Input Bias Current = \(\frac{{{{\rm{I}}_{b1}} + {{\rm{I}}_{b2}}}}{2}\)

= \(20 +22 \over 2\)

= 21 μA