Explanation:
- The majority carriers of charge in an n-p-n transistor are electrons, whereas, in a p-n-p transistor majority of charge carriers are holes. The mobility of electrons is more than that of holes because the holes have more effective mass than the effective mass of electrons.
- Thus n-p-n is preferred as in this electrons have higher mobility than holes, which results in high mobility of energy.
- In a p-n-p transistor, the positive supply line becomes a common point of input and output current, due to which the ground current is positive. This is inconvenient for design and maintenance.
- In an n-p-n transistor, the negative supply line becomes a common point of input and output current, due to which the ground current is negative. This is suitable for design and maintenance.
- Thus, n-p-n is suitable for negative ground current.
Hence, n-p-n is preferred over p-n-p.
Explanation:
- The majority carriers of charge in an n-p-n transistor are electrons, whereas, in a p-n-p transistor majority of charge carriers are holes. The mobility of electrons is more than that of holes because the holes have more effective mass than the effective mass of electrons.
- Thus n-p-n is preferred as in this electrons have higher mobility than holes, which results in high mobility of energy.
- In a p-n-p transistor, the positive supply line becomes a common point of input and output current, due to which the ground current is positive. This is inconvenient for design and maintenance.
- In an n-p-n transistor, the negative supply line becomes a common point of input and output current, due to which the ground current is negative. This is suitable for design and maintenance.
- Thus, n-p-n is suitable for negative ground current.
Hence, n-p-n is preferred over p-n-p.
