A solid copper sphere, 10 cm in diameter is deprived of 1020 electrons by a charging scheme. The charge on the sphere is
n 1020, Q = ne = e 1020 = 16.02 C.
Charge on sphere will be positive.
A lightning bolt carrying 30,000 A lasts for 50 microseconds. If the lightning strikes an airplane flying at 20,000 feet, what is the charge deposited on the plane?
If 120 C of charge passes through an electric conductor in 60 sec, the current in the conductor is
i = dQ/dt = 120/60 = 2A.
The energy required to move 120 coulomb through 3 V is
W = Qv = 360 J.
Consider the circuit graph shown in figure below. Each branch of circuit graph represent a circuit element. The value of voltage V1 is
100 = 65 + V2 => V2 = 35 V
V3 – 30 = V2 => V3 = 65 V
105 – V3 + V4 – 65 = 0 => V4 = 25 V
V4 + 15 – 55 + V1 = 0 => V1 = 15 V.
Req = ?
Req – 5 = 10(Req + 5)/(10 + 5 +Req). Solving for Req we have
Req = 11.18 ohm.
The superposition theorem requires as many circuits to be solved as there are
Twelve 6 resistor are used as edge to form a cube. The resistance between two diagonally opposite corner of the cube is (in ohm)
The energy required to charge a 10 µF capacitor to 100 V is
Energy provided is equal to 0.5 CVxV= 0.5x10-6 x 100 x 100 = 0.05 J
A capacitor is charged by a constant current of 2 mA and results in a voltage increase of 12 V in a 10 sec interval. The value of capacitance is ________
The capacitor current is given as i=C*(dv/dt), where dv/dt is the derivative of voltage, dt=t2-t1 given as 10 sec and dv is the change in voltage which is given as 12V.
So, we have C=i/(dv/dt)
=> C = 2mA/(12/10) = 2mA/(1.2).
Hence C = 1.67mF.