Assuming the operational amplifier to be ideal, the gain $${V_{out}}/{V_{in}}$$ for the circuit shown in figure

The circuit of fig shows a $$555$$ Timer $$IC$$ connected as an Astable multivibrator. The value of the capacitor $$C$$ is $$10$$ $$nF.$$ The values of the resistors $${R_A}$$ and $${R_B}$$ for a frequency of $$10$$ $$kHz$$ and a duty cycle of $$0.75$$ for the output voltage waveform are

For the circuit shown in figure with an ideal operational amplifier, the maximum phase shift of the output $${V_o}$$ with reference to the input $${V_{in}}$$ is

For the $$n$$-channel enhancement $$MOSFET$$ shown in figure,, the threshold voltage $${V_{th}}\,\, = \,\,2V.$$ The drain current $${I_D}$$ of the $$MOSFET$$ is $$4$$ $$mA$$ when the drain resistance $${R_D}$$ is $$1k\Omega .$$ If the value of $${R_D}$$ is increased to $$4\Omega ,$$ drain current $${I_D}$$ will become