MHT CET · Physics · Semiconductors
In an NPN transistor \(10^{10}\) electrons enter the emitter in \(10^{-6} \mathrm{~s}\) and \(2 \%\) electrons recombine with holes in base. The current ratios ' \(\alpha\) ' and ' \(\beta\) ' of a transistor are respectively (nearly)
- A \(0 \cdot 98,49\)
- B \(49,0.98\)
- C \(0 \cdot 49,98\)
- D \(98,0.49\)
Answer & Solution
Correct Answer
(A) \(0 \cdot 98,49\)
Step-by-step Solution
Detailed explanation
\(\mathrm{I}_{\mathrm{e}}=\frac{\mathrm{n}_{\mathrm{e}} \times \mathrm{e}}{\mathrm{t}} \text { and } \mathrm{I}_{\mathrm{c}}=\frac{\mathrm{n}_{\mathrm{c}} \times \mathrm{e}}{\mathrm{t}}\)
From the data given,
\(\begin{aligned}
I_c & =\frac{(98 / 100) n_e \times e}{t}=\frac{98}{100} I_c \\
\alpha & =\frac{I_c}{I_e}=\frac{98 I_e}{100 I_e}=0.98
\end{aligned}\)
\(\therefore \quad \beta=\frac{\alpha}{1-\alpha}=\frac{0.98}{1-0.98}=\frac{0.98}{0.02}=49\)
From the data given,
\(\begin{aligned}
I_c & =\frac{(98 / 100) n_e \times e}{t}=\frac{98}{100} I_c \\
\alpha & =\frac{I_c}{I_e}=\frac{98 I_e}{100 I_e}=0.98
\end{aligned}\)
\(\therefore \quad \beta=\frac{\alpha}{1-\alpha}=\frac{0.98}{1-0.98}=\frac{0.98}{0.02}=49\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- In a capillary tube of area of cross-section 'a' water rises to height 'h'. To what height will water rise in a capillary tube of area of cross-section \(4 a\) ?MHT CET 2025 Easy
- The mass and radius of the earth and moon are \(M, R\) and \(m, r\) respectively. The distance between their centers is \(d\). The minimum velocity with which a particle of mass \(m_0\) should be projected from the midpoint between them so that it could reach infinity isMHT CET 2022 Hard
- The magnetic flux (in weber) in a closed circuit of resistance \(20 \Omega\) varies with time \(t\) second according to equation \(\phi=5 t^2-6 t+9\). The magnitude of induced current at \(t=0.2\) second isMHT CET 2021 Easy
- Two small drops of mercury each of radius 'R' coalesce to form a large single drop.
The ratio of the total surface energies before and after the change isMHT CET 2020 Medium - In the circuit, current flowing through the circuit is
MHT CET 2024 Easy - A particle move in S.H.M. such that its acceleration is a \(=-\mathrm{px}\), where ' \(\mathrm{x}\) ' is the displacement of particle from equilibrium position and ' \(\mathrm{p}\) ' is a constant. The period of oscillation isMHT CET 2022 Medium
More PYQs from MHT CET
- How many faraday of electricity is required to produce \(10 \mathrm{~g}\) of calcium metal (molar mass \(=40 \mathrm{~g} \mathrm{~mol}^{-1}\) ) from calcium ions?MHT CET 2021 Medium
- Water rises up to a height \(h\) in a capillary tube immersed vertically in water. When this whole arrangement is taken to a depth \(d\) in a mine, the water level rises up to a height \(h^{\prime}\). If \(R\) is the radius of the earth, then the ratio \(\frac{h}{h^{\prime}}\) isMHT CET 2022 Hard
- A student measures time for 20 oscillations of a simple pendulum as \(30 \mathrm{~s}, 32 \mathrm{~s}, 35 \mathrm{~s}\) and 35 s . If the minimum division in the measuring clock is \(1 s\), then correct mean time (in second) isMHT CET 2025 Easy
- In an a. c. generator, when the plane of the coil is perpendicular to the magnetic fieldMHT CET 2024 Easy
- Which among the following is used as a monomer for the preparation of neoprene?MHT CET 2020 Easy
- Which of the following processes does not involve use of dihydrogen?MHT CET 2021 Hard