Exams › JEE Main › Physics

A transistor is used in common-base configuration and has a current gain of 0.96. If the emitter current is 7.2 mA, what is the base current?

0.29 mA
0.35 mA
0.39 mA
0.43 mA

Correct answer: 0.29 mA

Solution

Collector current Ic = alpha*Ie = 0.96*7.2 = 6.912 mA. Base current Ib = Ie - Ic = 7.2 - 6.912 = 0.288 ~ 0.29 mA.

Related JEE Main Physics questions

For a diode, the current–voltage relation is I = (e^(1000V/T) - 1) mA, where V is the applied voltage in volts and T is the temperature in kelvin. If the current is 5 mA at 300 K and the voltage measurement has an uncertainty of ±0.01 V, what is the resulting error in the current (in mA)?
A common-emitter amplifier has a current gain of 62. Its collector resistance is 5 kΩ and its input resistance is 500 Ω. If the applied input voltage is 0.01 V, what is the output voltage?
A half-wave rectifier employing a p-n junction diode is fed with an AC voltage of peak value 25 V and frequency 50 Hz. The circuit has no filter, and the load resistance is 1000 Ω. If the diode’s forward resistance R_f is 10 Ω, what is the rectification efficiency in percent?
At 27°C, germanium has an intrinsic conductivity of 2.13 mho m−1. If the electron and hole mobilities are 0.38 m2V−1s−1 and 0.18 m2V−1s−1, respectively, what is the charge-carrier concentration?
A transistor in good condition has its three terminals labeled P, Q, and R. When checked with a multimeter, there is no conduction between P and Q. However, if the negative lead of the meter is connected to R and the positive lead is connected to either P or Q, the meter shows some resistance. What can be concluded about the transistor?
At 300 K, intrinsic silicon has a hole concentration of 7 × 10¹⁵ m⁻³. If antimony is introduced into silicon at the rate of 1 atom per 10⁷ silicon atoms, and only one-half of the impurity atoms supply electrons to the conduction band, by what factor does the charge-carrier concentration rise because of doping? Take the number of silicon atoms in 1 m³ to be 5 × 10²⁸.

⚔️ Practice JEE Main Physics free + battle 1v1 →