Explanation: MOS transistors is formed as a sandwich consisting of a semiconductor layer, a silicon-di-oxide layer and a metal layer.

Explanation: In MOS transistors, polycrystalline silicon is used for their gate region instead of metal. Polysilicon gates have replaced all other older devices.

Explanation: The gate region is a sandwich consisting of semiconductor layer, an insulating layer and an upper metal layer.

Explanation: Electrical charge or current flows from source to drain depending on the charge applied to the gate region.

Explanation: Source and drain in the MOS transistors are doped with N-type material and substrate is doped with p-type material.

Explanation: In N channel MOSFET, source is the more negative of the elements and in the case of P channel MOSFET, it is the more positive of the elements.

Explanation: If the gate is given sufficiently large charge, the negative charge carreirs, electrons will be attracted from the bulk of the substrate material into the channel region below the oxide.

Explanation: Enhancement mode transistor acts as open switch whereas depletion mode transistor acts as normally closed switch.

Explanation: Depletion mode MOSFETs are more commonly used as resistors than as switches. As permanently on switch it has high resistance.

Explanation: Enhancement mode MOSFETs are more commonly used as switches and depletion mode devices are more used as resistors.

Explanation: Depletion mode transistors should be made large that is long and thin to create the large ‘on’ resistance.

Explanation: When driving a capacitive output load, charging time will be long compared to the discharging time.

Explanation: When the number of resistors per unit area increases, the device may not dissipate heat very well. This results in device overheating which leads to its failure.

Explanation: In all n channel MOSFET transistors, channel length is constant where as channel width can be varied.