Answer:

Explanation:
The capacitor of a parallel-plate capacitor is given by:

where
A is the area of each plate
d is the separation between the plates
is the vacuum permittivity
The energy stored in a capacitor instead is given by

where
Q is the charge stored in each plate
Substituting the expression we found for C inside the last formula,

And re-arranging it

Now if we substitute

We find the charge stored on the capacitor:

Answer:
<h2>
<em>6,142mm²</em></h2>
Explanation:
Given the dimension of a paper measured by a ruler as 7.4 cm wide and 8.3 cm long, the area of the paper is expressed using the area for calculating the area of a rectangle as shown;
Area of the piece of paper = Length * Width
Given length = 7.4cm
Length = 74mm (Since 10mm = 1cm)
Width = 8.3cm
Width (in mm) = 83mm
We converted to mm since the ruler used to measure has a division of 1mm.
Substituting the given values into the formula, we will have:
Area of the piece of paper = 74mm * 83mm
Area of the piece of paper = 6,142mm²
<em>Hence, the area of the piece of paper is 6,142mm²</em>
The fraction of radioisotope left after 1 day is
, with the half-life expressed in days
Explanation:
The question is incomplete: however, we can still answer as follows.
The mass of a radioactive sample after a time t is given by the equation:

where:
is the mass of the radioactive sample at t = 0
is the half-life of the sample
This means that the mass of the sample halves after one half-life.
We can rewrite the equation as

And the term on the left represents the fraction of the radioisotope left after a certain time t.
Therefore, after t = 1 days, the fraction of radioisotope left in the body is

where the half-life
must be expressed in days in order to match the units.
Learn more about radioactive decay:
brainly.com/question/4207569
brainly.com/question/1695370
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Answer:
changing the magnetic field more rapidly
Explanation:
According to Faraday's law, whenever there is a change in the magnetic lines of force, it leads the production of induced emf. The magnitude of induced emf is proportional to to the rate of change of flux.
Hence if the magnetic field inside a loop of wire is changed rapidly, the magnitude of induced emf increases in accordance with Faraday's law of electromagnetic induction stated above when the magnetic field is changed more rapidly, hence the answer.