Annie, a student of Physics, began her experiment by fabricating a p-n junction diode from an…
Annie, a student of Physics, began her experiment by fabricating a p-n junction diode from an extrinsic semiconductor crystal, leading to the formation of a depletion region and a potential barrier at the interface. She then measured resistance of the diode in the linear region of the V-I characteristic curve. She also studied its characteristics during forward bias and reverse bias. Finally, she designed a circuit to convert ac voltage to dc voltage.
Read the scenario given below and answer the questions that follow.
(i)[1.0]
Which instrument was used by Annie to measure current flowing through the diode during its reverse bias?
(ii)[1.0]
How did Annie obtain an extrinsic semiconductor from an intrinsic semiconductor?
(iii)[1.0]
What is meant by potential barrier?
(iv)[2.0]
Draw a labelled circuit diagram of a half wave rectifier.
Draw: labelled circuit diagram of a half wave rectifier
Must show: ac supply or transformer, p-n junction diode, load resistor RL, dc output across RL
Answer
Answer (i)
AIWritten by AI - it can contain mistakes.
A microammeter ($\mu\text{A}$) was used to measure the very small reverse current flowing through the diode.
Answer (ii)
AIWritten by AI - it can contain mistakes.
Annie obtained an extrinsic semiconductor by doping the pure (intrinsic) semiconductor—that is, by adding a controlled, minute quantity of a suitable impurity (such as trivalent or pentavalent atoms) into the intrinsic semiconductor lattice.
Answer (iii)
AIWritten by AI - it can contain mistakes.
Potential barrier is the potential difference established across the depletion layer of a p-n junction due to the accumulation of immobile ions, which opposes and prevents further diffusion of majority charge carriers across the junction.
From ISC 2026 Physics Paper 1, question 20.