Respuesta :
Answer:
a)
51764.7 ohm
b)
28.5 A
Explanation:
a)
t = time taken to charge to 90.0% of its final value = 16.2 s
T = time constant
C = capacitance = 136 x 10⁻⁶ F
R = resistance of the resistor
Q₀ = Maximum charge stored
Q = Charge after time "t" = 0.90 Q₀
Using the equation
[tex]Q = Q_{o}(1 - e^{\frac{-t}{T}})[/tex]
[tex]0.90 Q_{o} = Q_{o}(1 - e^{\frac{-16.2}{T}})[/tex]
[tex]0.90 = (1 - e^{\frac{-16.2}{T}})[/tex]
T = 7.04 s
Time constant is given as
T = RC
7.04 = R (136 x 10⁻⁶)
R = 51764.7 ohm
b)
V = Potential difference of voltage source = 265 volts
q = Amount of charge discharged = 0.90 Q₀ = 0.90 (CV) = (0.90) (136 x 10⁻⁶) (265) = 0.032436 C
t = time taken to discharge = 1.14 x 10⁻³ s
Current is given as
[tex]i = \frac{q}{t}[/tex]
i = 28.5 A
For the RC charging circuit of a camera flash unit has the value of resistance and current as,
- (a)The resistance R is 51765 ohms.
- (b) The average current delivered to the flash bulb is 28.5 ampere.
What is the formula of RC circuit?
RC circuit is the circuit in which the voltage or current passes through the resistor and capacitor consist by the circuit.
The formula for the RC circuit can be given as,
[tex]Q=Q_o\left(1-e^{\dfrac{-1}{RC}}\right )[/tex]
Here, [tex](Q_o)[/tex] is the initial charge and (R) is the resistance.
- (a)The resistance R-
The capacitor charges to 90.0% of its final value. Thus, the charge for the first case can be given as,
[tex]Q=0.90 Q_o[/tex]
The capacitance of 136 μF. Put the values in the above formula as,
[tex]0.90Q_o=Q_o\left(1-e^{\dfrac{-1}{R\times136\times10^{-6}}}\right )\\R=51765\rm ohm[/tex]
Thus, the value of the resistance R is 51765 ohms.
- (b) The average current delivered to the flash bulb-
The voltage source of the RC circuit is 265 V and the capacitor discharges 90.0% of its full charge in 1.14 ms. Thus, the amount of charge discharged is,
[tex]Q=0.9\times136\times10^{-6}\times265\\Q=3.2436\times10^{-2}\rm C[/tex]
The value of current is the ratio of discharge per second time (1.14 ms.). Therefore,
[tex]I=\dfrac{3.2436\times10^{-2}}{1.14\times10^{-3}}\\I=28.5\rm A[/tex]
Thus, for the RC charging circuit of a camera flash unit has the value of resistance and current as,
- (a)The resistance R is 51765 ohms.
- (b) The average current delivered to the flash bulb is 28.5 ampere.
Learn more about the RC circuit here;
https://brainly.com/question/15183130
