MCQ
An amplifier has a voltage gain $A_v = 1000$. The voltage gain in $dB$ is...........
- ✓$30$
- B$60$
- C$3$
- D$20$
✓
Answer
Correct option: A.
$30$
a
Voltage gain $= log\, 1000\, Bel$
$log\, 10^3 = 3Bel = 30\, dB$ $[1\, Bel = 10\, dB]$
Voltage gain $= log\, 1000\, Bel$
$log\, 10^3 = 3Bel = 30\, dB$ $[1\, Bel = 10\, dB]$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The figure shows a man of mass $m$ standing at the end $A$ of a trolley of mass $M$ placed at rest on a smooth horizontal surface. The man starts moving towards the end $B$ with a velocity $u_{rel}$ with respect to the trolley. The length of the trolley is $L$. The time taken by the man to reach the other end is
→If ${V_H},\,\,{V_N}$ and ${V_O}$ denote the root-mean square velocities of molecules of hydrogen, nitrogen and oxygen respectively at a given temperature, then
→The torque acting on a body about centre of mass due to normal reaction
A strap is passing over a wheel of radius $30\, cm.$ During the time the wheel moving with initial constant velocity of $2\, rev/sec.$ comes to rest the strap covers a distance of $25\, m.$ The deceleration of the wheel in $rad/s$$^2$ is
→A particle of charge $q$ and mass $m$ is moving along the $x$ -axis with a velocity $v$ and enters a region of electric field $E$ and magnetic field $B$ as shown in figure below for which figure the net force on the charge may be zero
→A signal of $100 \,THz$ frequency can be transmitted with maximum efficiency by
→As shown in the figure, in Young's double slit experiment, a thin plate of thickness $t =10\,\mu m$ and refractive index $\mu _{1}=1.2$ is inserted infront of slit $S _1$. The experiment is conducted in air $(\mu=1)$ and uses a monochromatic light of wavelength $\lambda=500\,nm$. Due to the insertion of the plate, central maxima is shifted by a distance of $x \beta_0 . \beta_0$ is the fringe-width before the insertion of the plate.The value of the $x$ is $.............$
→The refractive index of a particular material is $1.67 $ for blue light, $1.65$ for yellow light and $1.63$ for red light. The dispersive power of the material is .........
→A gas mixture consists of $2$ moles of oxygen and 4 moles of neon at temperature $T$. Neglecting all vibrational modes, the total internal energy of the system will be $...........\,RT$
→The mass of an $\alpha$-particle is
→