If the circuit shown has to function as a clamping circuit, which one of the following conditions should be satisfied for sinusoidal signal of period T?

In the ac equivalent circuit shown, the two BJTs are biased in active region and have identical parameters with β >> 1. The open circuit small signal voltage gain is approximately _______.

Assuming that the op-amp in the circuit shown below is ideal, the output voltage V₀ (in volts)

In the bistable circuit shown, the ideal opamp has saturation levels of $$ \pm 5V.$$ The value of R₁ (in k$$\Omega $$ ) that gives a hystersis width of 500 mV is ______