Complete question:
A 45-mH ideal inductor is connected in series with a 60-Ω resistor through an ideal 15-V DC power supply and an open switch. If the switch is closed at time t = 0 s, what is the current 7.0 ms later?
Answer:
The current in the circuit 7 ms later is 0.2499 A
Explanation:
Given;
Ideal inductor, L = 45-mH
Resistor, R = 60-Ω
Ideal voltage supply, V = 15-V
Initial current at t = 0 seconds:
I₀ = V/R
I₀ = 15/60 = 0.25 A
Time constant, is given as:
T = L/R
T = (45 x 10⁻³) / (60)
T = 7.5 x 10⁻⁴ s
Change in current with respect to time, is given as;
Current in the circuit after 7 ms later:
t = 7 ms = 7 x 10⁻³ s
Therefore, the current in the circuit 7 ms later is 0.2499 A
No one can really tell exactly how old the universe is. However, scientists have attempted to estimate the time by using the concept of Doppler effect which depends on the frequency of the stars and their relative velocities. From literature, the universe is about 13.82 billion years old. Thus, the age of the universe is 13.82×10⁹ times longer than a year.
Answer: Yes
Explanation:
does hot air rise
er substances, expands when heated and contracts when cooled. Because there is more space between the molecules, the air is less dense than the surrounding matter and the hot air floats upward. This is the concept used in the hot air balloons.
I believe the answer is D. Have a good day.
Answer:
d=20m/sx60s=1200m=1200/1000Km=1.2km
Explanation:
