Which of the following statements are true about semiconductors?

which of the following statements are true about semiconductor ? (a)silicon doped with electron rich impurity is a p-type semiconductor (b)Silicon doped with an electrons rich impurity is an n-type semiconductor (c)Delocalised electrons increase the conductivity of doped silicon (d)An electron vacancy increase the conductivity of n- type semiconductor

Which the following statements about are true

Which of the following statements are true about these isomers?

Which fo the following statement is true about friction:

Which of the following statements are true about exophthalamic goiter?