183. In semiconductors, resistivity
A. is the same as resistance.
B. depends on temperatrue.
C. is the same as mobility
D. increase as conductivity increases.

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184. In intrinsic semiconductors, conductivity
A. decreases as temperature increases.
B. is higher in silicon than in germanium at the same temperature.
C. depends on the intrinsic carrier concentration.
D. is the same as resistivity.

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185. For extrinsic semiconductors
A. the impurity-produced carriers greatly outnumber the thermally generated carriers.
B. the thermallY generated carriers.
C. the number of holes is equal to the number of free electrons
D. none of these

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186. Mobility in semiconductors
A. increase as temperature increases.
B. has no effect on resistivity.
C. has no effect on conductivity
D. decreases as temperature increases.

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187. Resistivity of an extrinsic semiconductor
A. changes more rapidly with change in temperature than does the resistivity of an intrinsic semiconductor.
B. dies not change as rapidly with changes in temperature as does the resistivity of an intrinsic semiconductor.
C. is greater than the resistivity of an undoped semiconductor.
D. does not depend on mobility.

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188. A doped semiconductor may be called intrinsic
A. when the thermally generated carriers become much greater than the impurity produced carriers.
B.( when the impurity-produced carriers become much greater than, the thermally generate carriers.
C. when the free-electron mobility equals the hole mobility
D. when conductivity equals resistivity.

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189. Carrier mobility depends on
A. resistivity and conductivity
B. recombination rate
C. charge per carrier
D. temperature and the regularity of the crystal structure.

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