Problem 116: Two point charges 10 cm apart exert a force of \(1 \times 10^{-3}\) grams on each other. If the charges are the same value, what is the value of each charge in stat coulomb?
A8.90 stat coulomb
B9.90 stat coulomb
C6.90 stat coulomb
D7.90 stat coulomb
#2📜 EE Board April 1997📘 1001 RojasEasy
Problem 117: Two electrons in a vacuum experience a force of \(2\times10^{-15}\) N. How far apart are the electrons?
A\(0.48\times10^{-7}\,m\)
B\(2.84\times10^{-12}\,m\)
C\(3.39\times10^{-7}\,m\)
D\(5.05\times10^{-12}\,m\)
#3📘 1001 RojasEasy
Problem 120: Calculate the magnitude of the electric field at a point that is 30 cm from a point charge \(Q=-3.2\times10^{-6}\,C\).
A\(3.2\times10^6\,N/C\)
B\(3.0\times10^5\,N/C\)
C\(2.8\times10^6\,N/C\)
D\(2.4\times10^5\,N/C\)
#4📜 EE Board October 1991📘 1001 RojasEasy
Problem 122: Calculate the capacitance between two parallel plates each of which is \(100\,\text{cm}^2\) and 2 mm apart in air.
A\(0.443\,\mu\mu F\)
B\(0.515\,\mu\mu F\)
C\(0.452\,\mu\mu F\)
D\(0.502\,\mu\mu F\)
#5📜 EE Board October 1997📘 1001 RojasEasy
Problem 127: A capacitor is charged with 0.23 watt-second of energy at a voltage of 48 volts. What is its capacitance?
A180 \(\mu F\)
B240 \(\mu F\)
C200 \(\mu F\)
D220 \(\mu F\)
#6📜 EE Board October 1997📘 1001 RojasEasy
Problem 128: A 20 \(\mu F\) capacitor is charged by a 12-V battery. What is the stored energy in the capacitor?
A\(1.07\times10^{-3}\,J\)
B\(2.88\times10^{-2}\,J\)
C\(2.88\times10^{-3}\,J\)
D\(1.44\times10^{-3}\,J\)
#7📘 1001 RojasEasy
Problem 130: A capacitor whose plates is 20 cm x 3.0 cm and is separated by a 1.0-mm air gap is connected across a 12-V battery. Determine the charge accumulated on each plate after a long time.
A\(5.3\times10^{-12}\,C\)
B\(7.2\times10^{-9}\,C\)
C\(8.1\times10^{-11}\,C\)
D\(6.4\times10^{-10}\,C\)
#8📜 EE Board October 1990📘 1001 RojasEasy
Problem 131: The result of capacitance \(C_1 = 6\) microfarads and \(C_2\) connected in series is 3 microfarads. Capacitor \(C_2\), in microfarads is
A3
B4
C8
D6
#9📘 1001 RojasEasy
Problem 138: Four capacitors A, B, C and D are connected across a 150-V DC source. The charges accumulated in A, B and C are equal to 2000, 750 and 1500 \(\mu C\), respectively. If the total capacitance of the combination is known to be 35 \(\mu F\), how much charge is the accumulated in capacitor D?
A1200 \(\mu C\)
B1000 \(\mu C\)
C1150 \(\mu C\)
D1400 \(\mu C\)
#10📜 EE Board October 1993📘 1001 RojasEasy
Problem 139: A condenser of 1 microfarad capacitance is charged to 100 volts and then disconnected from the power supply. A second but uncharged capacitor of 3 microfarad is then connected across the first capacitor. The voltage across the parallel combination is
A66 2/3 volts
B45 volts
C25 volts
D110 volts
#11📜 EE Board October 1994📘 1001 RojasEasy
Problem 140: Three capacitors A, B and C are charged as follows: A = 10 \(\mu F\), 100 V; B = 15 \(\mu F\), 150 V and C = 25 \(\mu F\), 200 V. They are connected in parallel with terminals of like polarity together. What is the voltage across the combination?
A150 V
B120 V
C185 V
D165 V
#12📘 1001 RojasEasy
Problem 141: A 100 \(\mu F\) capacitor is charged from a 200-V supply. The charged capacitor is then connected across three uncharged capacitors connected in parallel. The charges on these capacitors after a long time become 4000, 5000 and 6000 \(\mu C\). Solve the voltage across the combination.
A64 V
B50 V
C76 V
D80 V
#13📜 EE Pre-Board August 2012📘 PowerhouseEasy
The electric potential at appoint in air due to a charge is 21 V. If air is replaced by a medium of relative permittivity of 3, then the electric potential at that point will be _ .
A63 V
B7 V
C21 V
D42 V
#14📜 EE Pre-Board March 2013📘 PowerhouseEasy
The area of one plate of a two plate mica capacitor is 0.0025 m² and the separation between plates is 0.02 m. If the dielectric constant of mica is 5, what is the capacitance of the capacitor?
A5.53 μF
B5.53 pF
C7.74 μF
D7.74 pF
#15📜 EE Pre-Board August 2013📘 PowerhouseEasy
Two capacitors \(C_1\) and \(C_2\) are connected in series across a 240 V source. If \(C_1\) is 24 μF and the total capacitance is 6 μF, find the voltage across \(C_2\).
A240 V
B60 V
C180 V
D120 V
#16📜 EE Pre-Board August 2013📘 PowerhouseEasy
A capacitor is charged with 250 coulombs in 5 seconds. What is the charging current?
A25 A
B50 A
C500 A
D1,250 A
#17📜 EE Pre-Board March 2014📘 PowerhouseEasy
Three capacitors are connected in parallel: \(C_1\) = 12 μF, \(C_2\) = 10 μF and \(C_3\) = 40 μF. What is the total capacitance?
A45 μF
B5 μF
C10 μF
D62 μF
#18📜 EE Pre-Board March 2014📘 PowerhouseEasy
The voltage across a 50 μF capacitor rises at a constant rate of 10 V/ms. Calculate the current through the capacitor.
A2 mA
B5 mA
C50 mA
D500 mA
#19📜 EE Pre-Board August 2014📘 PowerhouseEasy
Two capacitors \(C_1\) = 100 μF and \(C_2\) = 50 μF are placed in series. Find the maximum energy stored when a 220 V dc supply is applied across the combination.
A0.107 J
B0.507 J
C0.807
D1.107 J
#20📜 EE Pre-Board August 2014📘 PowerhouseEasy
Calculate the capacitance of a parallel plate capacitor having 20cm x 20cm square plates separated by a distance of 1mm. Assume the dielectric medium to be air.
