Answer:
The current in the circuit at a time interval of τ seconds after the switch has been closed is 0.123 A
Explanation:
The time constant for an R and C in series circuit is given by τ = RC.
R = 3000 ohms, C = 0.5 × 10⁻⁶ F = 5.0 × 10⁻⁷ F
τ = 3000 × 5 × 10⁻⁷ = 0.015 s
The voltage across a capacitor as it charges is given be
V(t) = Vs (1 - e⁻ᵏᵗ)
where k = 1/τ
At the point when t = τ, the expassion becomes
V(t = τ) = 1000 (1 - e⁻¹) = 0.632 × 1000 = 632 V
Current flows as a result of potential difference,.
Current in the circuit at this time t = τ is given by
I = (Vs - Vc)/R
Vs = source voltage = 1000 V
Vc = Voltage across the capacitor = 632 V
R = 3000 ohms
I = (1000 - 632)/3000 = 0.123 A
The principle that
describes the force on a charge in a magnetic field was named for Hendrik Lorentz, and the principle
is named as Lorentz force.
Hendrik Antoon Lorentz<span> <span>(18 July 1853 – 4 February 1928) was a Dutch </span></span>physicist<span> <span>who shared the 1902 </span></span>Nobel Prize in Physics<span> <span>with </span></span>Pieter Zeeman<span> <span>for the discovery and theoretical explanation
of the </span></span>Zeeman effect<span>.<span> </span></span>
F = ma = m dv/dt
F dt = m dv
integrate both sides ( assuming constant force , mass) , zero inital conditions
Ft = mv
mv = P
P = Ft = 5 * 100 = 500 N.s
The resistance of a wire is given by
where
is the resistivity of the material, L the length of the wire and A its cross-sectional area.
In the problem,
and L remain the same, while A changes because the radius changes. The area is given by:
This means that if we double the radius (2r), the area becomes
And therefore, the new value of the resistance is
So, when the radius is doubled, the resistance becomes
of its original value.
Answer:
5 km/hr because he thinks it moves in the same speed of his...
