The circuit diagram shown here corresponds to the logic gate,

Case-1 : A = 0, B = 0
LED will glow
Y=1

Case-2 : A = 0, B = 1
No current will flow through LED

$\therefore \mathrm{Y}=0$

Case-3 : A = 1, B = 0
Again no current will through LED

$\therefore \mathrm{Y}=0$

Case-4 : A = 1, B = 1
Again Y = 0

NOR gate