Questions

p type of semiconductor is obtained when Silicon is doped with a trivalent impurity like Aluminium. Aluminium is a p-type dopant, which means that when a semiconductor i.e. silicon is doped with aluminium, it creates a hole (positively charged carrier) by accepting an electron from the silicon atom. Electrical conductivity of semiconductors increasesand resistivity remains the same

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

It returns -1

Government can be classified in three manners:

(1) who participates,

(2) geographic distribution of power, and

(3) legislative/executive relationship.

Who can participate is generally broken down into two forms of government,

democracy or dictatorship

While the legislative/executive relationship is broken down into

presidential or parliamentary

The geographic distribution of power is broken down into unitary, federal, and confederation (confederal).

Confederal System of Government ::

A system of government where power is located with the independent states and there is little power in the central government.

Today, no nation follows a confederal system. Organizations, like the European Union and the Commonwealth of Independent States, are based on the ideas of a confederal system. Several nations make up these organizations, but they still retain the majority of their independence.

Nucleus serves as the control center for cell metabolism and reproduction.

When a running car stops suddenly, the passengers tends to lean forward because of Inertia of motion.

Life Cycle costing includes the costs from each phase of the project life cycle when the total investment costs are calculated. Answer A is incorrect because an opportunity cost is the difference between a chosen investment and the one that is passed up. Answer B is incorrect because sunk costs are costs that have been incurred and cannot be reversed. Answer C is incorrect because net present value (NPV) is the present value of cash inflows(benifits) minus the present value of cash outflows (costs).