While teaching about transistors, mrs.. kwon shows a video of a hand pump being used to draw water from a well. she points out how the person primes the pump by pouring a smal amount of water into it before the water would start to flow. what does the water used to prime the pump represent? a. the current in the emitter that amplifies the signal b. the current in the base that amplifies the signal c. the current in the collector that turns the transistors on d. the current in the base that turns the transistors on

d. the current in the base that turns the transistors on.

While using Transistor as switch, in the switch off state the current in base is 0. To switch on the transistor, a current at base is required that allows the flow of current through the transistor like a small amount of water is poured to prime the pump. The current won't flow through the transistor unless the biasing of base allows the current.

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.