The statement to be judged combines two independent comparisons between the bipolar junction transistor (BJT) and the field-effect transistor (FET): switching speed and power consumption. Both parts must be correct for an option to be correct.

1. Speed — why the BJT is slower. A BJT is a bipolar, minority-carrier device: conduction relies on minority carriers injected into the base. When the transistor is driven into saturation, excess minority charge is stored in the base region, and to turn the device OFF this stored charge must first be removed. That gives rise to the storage time t_s, which dominates the turn-off delay:

\(t_{off} = t_s + t_f\)

A FET is a unipolar, majority-carrier device — current is carried by electrons in an n-channel (or holes in a p-channel) drifting under the gate field, with essentially no minority-carrier injection and therefore no storage delay. Its switching is limited only by charging and discharging the gate capacitance, which is fast. Hence the FET switches faster than the BJT.

2. Power — why the BJT consumes more. To keep a BJT ON you must supply a continuous base current

\(I_B = \dfrac{I_C}{\beta}\)

through a forward-biased base–emitter junction, so the input itself dissipates power all the time the device conducts. Its input resistance is only a few kΩ. A FET is controlled by the voltage on a reverse-biased (JFET) or insulated (MOSFET) gate; the gate current is in the pA–nA range and the input resistance is 10⁸–10¹² Ω, so the steady-state control power is negligible. Hence the BJT consumes more power than the FET.

Judging the options. Options 3 and 4 claim the BJT is faster, which contradicts the minority-carrier storage argument. Option 2 claims the BJT consumes less power, which contradicts the continuous base-current requirement. Only option 1 gets both halves right.

Related contrasts worth remembering. The FET also has lower noise (no junction-current shot noise from a forward-biased junction), a negative temperature coefficient of drain current that prevents thermal runaway, and better tolerance of radiation; the BJT in exchange offers much higher transconductance g_m for a given current and better device matching, which is why analog designers still use it.

Hence, the correct statement is that the BJT is slower than the FET and its power consumption is larger than that of the FET.