Why is the linear portion of the triode characteristic chosen to operate the triode as an amplifier?

Two charged conducting spheres of radii a and b are connected to each other by a wire. What is the ratio of electric fields at the surfaces of the two spheres? Use the result obtained to explain why charge density on the sharp and pointed ends of a conductor is higher than on its flatter portions.

Consider the circuit arrangement shown in figure (1) for studying input and output characteristics of n-p-n transistor in CE configuration. Select the values of R_(B) and R_(C ) for a transistor whose V_(BE)=0.7V , so that the transistor is operating at point Q as shown in the characteristics shown in figure (2). Given that the input impedance of the transistor is very small and V_(C C)=V_(BB)=16V , also find the voltage gain and power gain of circuit making appropriate assumptions.

Why is I to V characteristic of a solar cell draw in the fourth quadrant of the coordinate system?

Gently strike a hanging bell (temple bell) and try to listen to the sound produced by it with a stethoscope keeping it both at bottom portion and top portion of the bell. Is the pitch and loudness of the sound same at the two portions ? Why ?