The current i_b through the base of a silicon npn transistor is $$1\;+\;0.1\;\cos\left(10000\;\mathrm\pi\;\mathrm t\right)$$ mA . At 300 K, the $$r_\mathrm\pi$$ in the small signal model of the transistor is

In the circuit shown below, capacitors C₁ and C₂ are very large and are shorts at the input frequency. V_i is a small signal input. The gain magnitude $$\left|\frac{{\mathrm V}_0}{{\mathrm V}_\mathrm i}\right|$$ at 10 Mrad/s is

In the silicon BJT circuit shown below, assume that the emitter area of transistor Q₁ is half that of transistor Q₂.The value of current I₀ is approximately

The amplifier circuit shown below uses a silicon transistor. The capacitors C_C and C_E can be assumed to be short at signal frequency and the effect of output resistance r₀ can be ignored. If C_E is disconnected from the circuit, which one of the following statements is TRUE?