If the base resistor has zero resistance, the transistor will probably be

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Destroyed

Explanation: If the base resistor is zero, the Base-Emitter junction of the BJT acts as a forward-biased diode connected directly to the voltage source. Without a current-limiting resistor, the base current ($I_B$) will exceed the transistor's maximum rated current limit, leading to thermal runaway or internal structural failure.

Working Principle: In a BJT circuit, the base resistor serves to limit the input current to a safe operating level defined by Ohm's Law ($I_B = \frac{V_{in} - V_{BE}}{R_B}$). By setting $R_B = 0$, the base current is theoretically limited only by the source impedance and the small internal resistance of the junction, causing an massive surge in current that exceeds the power dissipation capacity ($P_D = V_{CE} \cdot I_C + V_{BE} \cdot I_B$) of the device, effectively burning out the junction.

Key Formulas: $I_B = \frac{V_{in} - V_{BE}}{R_B}$ — Base current equation for a common-emitter configuration; $P_D = V_{BE}I_B + V_{CE}I_C$ — Power dissipation formula causing thermal stress

Key Points: The base-emitter junction is effectively a forward-biased p-n junction with a very low turn-on voltage ($\approx 0.7V$ for Silicon).; A base resistor is mandatory to protect the BJT from excessive current damage.; Without resistance, the low dynamic impedance of the junction causes a destructive current spike.

Disadvantages: Permanent hardware failure; Thermal damage to semiconductor substrate

Additional Info: The BJT is a current-controlled device; therefore, controlling base current is critical.. Option A is incorrect because saturation occurs when $I_B$ is sufficient to make $V_{CE}$ low, but zero resistance causes current far beyond saturation, leading to failure.

Answer: C is correct — connecting the base directly to the supply without a resistor leads to excessive current flow that destroys the transistor's internal junction.

Exam Tip: In competitive exams, always identify 'current-limiting' components. A BJT base circuit without a resistor is a classic 'trap' question indicating immediate physical damage.

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