Answer:
because the focal length is negative.
Explanation:
Power of a lens (P) is the reciprocal of its focal length (f).
In electrical circuit, this arrangement is called a R-L series circuit. It is a circuit containing elements of an inductor (L) and a resistor (R). Inductance is expressed in units of Henry while resistance is expressed in units of ohms. The relationship between these values is called the impedance, denoted as Z. Its equation is
Z = √(R^2 + L^2)
Z = √((1.24×10^3 ohms)^2 + (6.95×10^-6 H)^2)
Z = 1,240 ohms
The unit for impedance is also ohms. Since the circuit is in series, the voltage across the inductor and the resistor are additive which is equal to 12 V. Knowing the impedance and the voltage, we can determine the maximum current.
I = V/Z=12/1,240 = 9.68 mA
But since we only want to reach 73.6% of its value, I = 9.68*0.736 = 7.12 mA. Then, the equation for R-L circuits is

, where τ = L/R = 6.95×10^-6/1.24×10^3 = 5.6 x 10^-9
Then,
t = 7.45 nanosecondsPart B.) If t = 1.00τ, then t/τ = 1. Therefore,
I = 6.12 mA
Answer:
the current is 3.5 A
Explanation:
The computation of the current is shown below:
As we know that
Current [A] = Electrical power [W] ÷ Potential difference [V]
Now convert KW TO W = × 1000
So, the current is
= 800W ÷ 230V
= 3.5 A
Hence, the current is 3.5 A
It is false. Because the amount of energy carried in the wave is inversely related to the length of the waves wavelength. To correct the statement it should be that the shorter the radiation's wavelength the stronger is the radiation's energy.