Given :
Number of operations move through a pocket calculator during a full day's operation ,
.
To Find :
How many coulombs of charge moved through it .
Solution :
We know , charge in one electron is :

So , charge on n electron is :

Therefore , -21.44 coulombs of charge is moved through it .
Hence , this is the required solution .
Move the decimal point to:
Left : (if the exponent of ten is a negative number -) ... OUR CASE HERE (-2)
or to
Right : (if the exponent is positive +).
You should move the point as many times as the exponent indicates.
Do not write the power of ten anymore.
So, standard form is:
Two points to the left {Exponent of Ten is Negative (-2)}
0.059 ... (without the 10)
Answer:
D) Q/2
Explanation:
The relationship between charge Q, capacitance C and voltage drop V across a capacitor is
(1)
In the first part of the problem, we have that the charge stored on the capacitor is Q, when the voltage supplied is V. The capacitance of the parallel-plate capacitor is given by

where
is the vacuum permittivity, A is the area of the plates, d is the separation between the plates.
Later, the voltage of the battery is kept constant, V, while the separation between the plates of the capacitor is doubled:
. The capacitance becomes

And therefore, the new charge stored on the capacitor will be

Answer:
The correct answer is "53.15 days".
Explanation:
Given that:
Half life of
,

- Let the initial activity be "
". - and, activity to time t be "R".
To find t when R will be "1%" of
, then
⇒ 
As we know,
⇒ 
or,
∴ 
By putting the values, we get


We know that,
Decay constant, 
hence,
⇒ 

