Answer:
Explanation:
According to Gauss's theorem , total flux coming out of a closed surface area is equal to 1/ε₀ times charge enclosed
This flux coming out of enclosed charge does not depend upon the shape of enclosing surface area . It only depends upon the charge enclosed .
It the present context , in both the case ie in case of donut or sphere , since amount of charge enclosed is same , flux coming out too will be same in both the case
Hence the required ratio = 1 : 1
Answer:
R/2
Explanation:
Resistance of full lenght wire = R
Since length is divided into half but even then the resistance of each individual half is same i-e R
If connecetd into parallel mode then we know resultant resistance say 'r' is
1/r=1/R+1/R
or
1/r = 2/R
r= R/2
Answer:
3
Explanation:
The half-life is the time it takes for the amount of radioactive isotope to halve. Therefore, we have:
- After 1 half-life, only 1/2 of the element will be left
- After 2 half-lives, only 1/4 of the element will be left
- After 3 half-lives, only 1/8 of the element will be left
So, it will take 3 half-lives for the element to become 1/8 of its original amount.
Mathematically, this can be also verified by using the equation
where
N(t) is the amount of the element left at time t
N0 is the initial amount of the element
is the half-life
Substituting (3 half-lives), we find