What is the magnitude and unit of `epsilon_0`?

What is the magnitude of a unit vector ?

The position of a particle is given by r=3.0t hati - 2.0t^2 hatj + 4.0 hatk m where tis in seconds and the coefficients have the proper units for r to be in metres:- What is the magnitude and direction of velocity of the particle at t = 2.0 s ?

What is the SI unit of epsilon_0 ?

What is the dimensional formula for epsilon_0 ?

Show that during the charging of parallel plate capacitor,the rato of charging of a prallel plate capacitor,the rate of change of charge on each plate equals epsilon_0 times the rate of change of electric flux (phi_E) linked with it .What is the name given to the term epsilon_0 (dphi _E)/(dt) ?

What is the magnitude of magnetic force per unit length on a wire carrying a current of 8 A and making an angle of 30^@ with the direction of a uniform magnetic field of 0.15 T?

What affects the magnitude of surface tension of a liquid ?