Question

If the current in the circuit decreases, what does that mean about the rate at which the charge(and voltage) change in a capacitor?
2. the exponent of the exponential function contains RC for the given circuit. who's is a constant. use units R and C to find units of RC. write ohms in terms of volts and amps and write farads in terms of volts and coulombs. Simplify
units of RC are__________

Answer 1

Answer:

`1. charge Q, on the capacitor increases, while the current will decrease

2. τ = t = secs

Explanation:

1. consider RC  of a circuit to be am external source

voltage across the circuit is given as

v =v₀(1 - $e^{\frac{t}{τ} }$)

where v = voltage

v₀ = peak voltage

t = time taken

τ= time constant

as the charge across the capacitor increases, current decreases

the charge across the circuit is given as

Q= Q₀(1 - $e^{\frac{t}{τ} }$)

charge Q is inversely proportional to the current I

hence the charge across the circuit increases

2. τ = RC

unit of time constant, τ,

= Ω × F

=$\frac{V}{I}$ ˣ $\frac{C}{V}$

=$\frac{C}{A}$

=$\frac{C}{C/t}$

τ = t = secs