Problem 417: A series RL circuit is connected across a dc source through a switch. Three (3) milliseconds after the switch is closed, the voltage across the inductance is 20 V and drops to 5 V after 20 ms. If R = 100 ohms, find L. Assume at t = 0, I = 0.
A1.30 H
B1.22 H
C1.59 H
D1.25 H
#2📜 EE Board October 1992📘 1001 RojasHard
Problem 425: An uncharged condenser in series with a 120-volt voltmeter of 10,000 ohms resistance is suddenly connected to a 100 V battery. One second later, the voltmeter reads 60 volt. Determine the rate at which the voltage across the condenser is charging.
A51e\(^{-0.55t}\)
B51e\(^{-0.51t}\)
C55e\(^{-0.55t}\)
D55e\(^{-0.51t}\)
#3📘 1001 RojasHard
Problem 431: A series RLC circuit with R = 1 k\(\Omega\), L = 1 H and C = 6.25 \(\mu\)F is suddenly connected across a 24 V dc source. At t = 0, I = 0 and q = 0. Determine the current after 0.01 sec.
A3.45 mA
B4.61 mA
C5.40 mA
D5.05 mA
#4📘 1001 RojasHard
Problem 432: A series RLC circuit has R = 200 \(\Omega\), L = 0.1 H and a capacitor C = 10 \(\mu\)F. If a 100 V dc source is connected across the end terminals of the series circuit at t = 0, determine the current after 1 millisecond. Assume zero initial conditions.
A0.353 A
B0.229 A
C0.253 A
D0.368 A
#5📘 1001 RojasHard
Problem 433: A series RLC circuit has R = 40 ohms, L =100 mH and C = 50 \(\mu\)F. The circuit is connected across a 100 V dc source at t = 0 through a switch. Determine the current 0.02 second after the switch is closed. Assume all initial condition to be zero.
A6.40 mA
B5.31 mA
C6.22 mA
D4.85 mA
#6📜 EE Board April 1991📘 1001 RojasHard
Problem 435: A certain electric welder has a basic circuit equivalent to a series RL with R = 0.1 \(\Omega\) and L = 1 mH. It is connected to an AC source "e" through a switch "s" operated by an automatic timer, which closes the circuit at any desired point on the 60 cycle, sinusoidal wave "e". Calculate the magnitude of the transient current resulting when "s" closes as "e" is passing through its peak value of 100 volts.
A256.41 A
B65.74 A
C80.54 A
D76.32 A
#7📘 1001 RojasHard
Problem 437: A series RC circuit with R = 30 ohms and C = 250 \(\mu\)F is connected across an AC voltage source of emf 100 sin 100t through a switch. The switch is closed at t = 0. Determine the current when t = 0.01 second. Assume at t = 0, voltage across the capacitor is zero.
A1.45 A
B1.24 A
C0.93 A
D2.05 A
#8📘 1001 RojasHard
Problem 440: A series RL circuit has R = 10 ohms and L = 1 henry. The circuit is connected across a voltage source \(e(t)=10e^{-10t}\) through a switch that is initially open. The switch is closed at t = 0. Determine the current after 0.01 second. Assume initial current to be zero.
A86.8 mA
B90.5 mA
C89.3 mA
D92.2 mA
#9📜 EE Pre-Board March 2014📘 PowerhouseHard
A 100 μF capacitor initially charged to 24 V is discharged across a series combination of a 1 kΩ resistor and a 200 μF capacitor. Find the current after 1 sec.
