Are silent run on power and have to be electricly charged
Good conductors are the materials which allow electricity to pass through them easily whereas, bad conductors are the materials which do not allow electricity to pass through them. Good conductors offer less resistance to the flow of current, whereas the bad conductors do not transmit current through them.
In atoms, electrons surround the nucleus in specific energy levels.
Answer: Option B
<u>Explanation:
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Atom, actually considered as the tiny part that is ever present in this universe. Many theories and experiments were conducted, for studying what was present inside of an atom, and many theories came into light.
And finally, Bohr-Sommerfeld Theory stated the final conclusion, that the positive charge is at the centre of the nucleus, and all the electrons revolve in their specific energy levels. If an atom wants to move to lower energy state, it should emit energy, whereas for going to higher state, it should gain energy.
Answer:
Minimum time = 1.95x10^-4 s
Number of pulses = 5128.21 pulses/s
Explanation:
We have the speed of sound waves through human tissue with a value of 1540 m/s, to calculate the time it takes for the pulse to travel a distance of 30 cm (since the pulse will first travel a distance of 15 cm and then it will return another 15 cm to be detected by the equipment), therefore, the time between the two pulses will be equal to:
tminimum = 0.30 m/1540 m/s = 1.95x10^-4 s
To calculate the number of pulses, one second must be divided over the minimum time between the two pulses, as follows:
npulses = 1 s/1.95x10^-4 s = 5128.21 pulses/s
Photon has no rest mass but when photon travels at the speed of light, it gains momentum.
The energy of the photon is E= pc, c = speed of the photon and p= its momentum.
∴ E = pc
but p = h/λ (This comes from De-broglie's theory)
∴ E = hc/λ
frequency = ν = c/λ
∴E = hν
