. Which of the following is wrong for a transistor?
(a)The ratio of change in collector-emitter voltage (ΔVCE) to the change in collector current (ΔIC) at a constant base current IB is called output resistance (r0).
(b)The ratio of change in base-emitter voltage (?VBE) to the resulting change in base current (ΔIB) at constant collector-emitter voltage (VCE) is known as input resistance (ri).
(c)The ratio of change in base current to the change in collector current is defined as the current amplification factor (β).
(d)A transistor acts as an amplifier when operated in the active region.