Question

a) If a charge of 1000 Coulombs flows across a given point in 2 seconds, find the electric current in amperes.

b) Determine the emf required so that 13 mA can pass through a resistor of 200Ω. If that same emf is applied to a resistor of 1kΩ, find the new current.

Answer 1

Solution.

$a) Q=1000 C;$

$t=2 s;$

$I=\dfrac{Q}{t};$

$I=\dfrac{1000C}{2s}=500A;$

$b) I=13 mA=0.013A;$

$R=200\Omega;$

$U=IR;$

$U=0.013A\sdot200\Omega=2.6V;$

$R=1000\Omega;$

$U=0.013A\sdot1000\Omega=13V.$

Answer: $a) I=500A;$

$b) U=2.6V; 13V.$