The answer is B I think sorry if it’s wrong
The British physicist Joseph John (J. J.) Thomson (1856–1940) performed a series of experiments in 1897 designed to study the nature of electric discharge in a high-vacuum cathode-ray tube, an area being investigated by many scientists at the time. Thomson's model showed the atom as a positively charged ball of matter with negatively changed electrons floating freely around inside of it. This model showed the atom having no structure. There are also no protons and neutrons in this model. Thomson knew that the atom had positively and negatively charges particles in it he just didn't know how they were arranged. <span>Today's model gives us a much clearer picture of the atom. There is a positively charged center of the atom that is denser than the rest of it called the nucelus. This dense center is made up of positively charged protons and neutrally charged neutrons. Around the outside of the nucleus the electrons are organized on rings. These electrons are arranged in a certain pattern that is the same for all atoms.</span>
The distance travel is 69.5 meters.
<u>Explanation:</u>
Given datas are as follows
Speed = 27.8 meters / second
Time = 2.5 seconds
The formula to calculate the speed using distance and time is
Speed = Distance ÷ Time (units)
Then Distance = Speed × Time (units)
Distance = (27.8 × 2.5) meters
Distance = 69.50 meters
Therefore the distance travelled is 69.50 meters.
As we know that in transformers we have

here we know that




now from above equation we will have


now we have to reduce this voltage to final voltage of V = 4 V
so again we will have



so we need to take such a winding whose ratio is 1:5
So it is satisfied in X


so answer will be
<u>B)- X</u>
Answer:
decibel gain is 10 db
Explanation:
given data
voltage v1 = 5 volts
voltage v2 = 15 volts
to find out
decibel gain
solution
we have given that 5 volt voltage that is increase to 15 volts
so
we know here decibel gain formula that is
decibel gain = 20 log(v2/v1) ....................1
put here value of v1 and v2 in equation 1
decibel gain = 20 log(15/5)
decibel gain = 20 log3
decibel gain = 20 × 0.4771
decibel gain = 9.54 db = approx 10 db
so decibel gain is 10 db