$$IC$$ $$555$$ in the adjacent figure is configured as an Astable multivibrator. It is enabled to oscillator at $$t=0$$ by applying a high input to pin $$4.$$ The pin description is $$1$$ and $$8$$ $$-$$supply; $$2-$$trigger; $$4-$$reset; $$6$$-threshold; $$7$$-discharge. The wave form appearing across the capacitor starting from $$t=0$$ as observed on the storage $$CRO$$ is

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