Tag: system of unit

Questions Related to system of unit

SI unit of Magnetic flux is weber and its CGS unit is maxwell. Then 1 Wb = :

physics dynamics - explaining motion system of unit summary of si units system of units

  1. $10^6$ maxwell

  2. $10^7$ maxwell

  3. $10^8$ maxwell

  4. $10^9$ maxwell

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Correct Option: C
Explanation:

Magnetic flux is the product of magnetic field and area.

As SI unit of magnetic flux is weber, so $1 \, Wb=Tesla (T)\times m^2$
where $1 \, T=10^{4} \, gauss$ and $1 m^2=10^4 cm^2$
(T and gauss is the SI and CGS unit of magnetic field )
So, $1 \, Wb=10^4 \, gauss \times 10^4cm^2=10^8 $ maxwell

$S = A(1 - e^{-Bxt})$, where S is speed and x is displacement. The unit of B is :

physics dynamics - explaining motion system of unit summary of si units system of units

  1. $m^{-1}s^{-1}$

  2. $m^{-2}s$

  3. $s^{-2}$

  4. $s^{-1}$

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Correct Option: A
Explanation:

It is given that $x$ is displacement and $t$ is time.
Unit of $x$ is $m$ and that of time t is $s$.
Since, the quantity $Bxt$ must be dimensionless.
$\implies$ Unit of B must be $m^{-1}s^{-1}$.