The truth table given in fig. represents :

A	B	Y
0	0	0
0	1	1
1	0	1
1	1	1

The temperature dependence of resistance of $$Cu$$ and undoped $$Si$$ in the temperature range $$300-400$$ $$K,$$ is best described by :

If $$a, b, c, d$$ are inputs to a gate and $$x$$ is its output, then, as per the following time graph, the gate is :

Identify the semiconductor devices whose characteristics are given below, in the order $$(a), (b), (c), (d)$$ :