An apparatus is designed to judge the accuracy with which humans can judge time-intervals.
Pressing a pushbutton (A) allows current to flow from a 15V supply rail, via a 15kΩ resistor into an earthed 1mF capacitor.
The capacitor voltage Vc is monitored by a voltmeter, and can be reset to zero by means of another pushbutton (B).
Neatly sketch the circuit.
At time zero, button B is pressed.
At time t = 1 button A is pressed an held down
At time t = 3 button A is released.
At time t = 5 button B is pressed again.
Sketch a graph showing how the capacitor voltage varies over the period t = 0 to 6 seconds.
(Correct answer attached).
I am not sure of a couple of things:
*If both button A and B are held down at the same time, will there be 2 currents (one flowing into the capacitor, and the other following to B's earth line, simultaneously)?
*When the current flows through the capacitor to earth, howcome the current doesnt travel past the capacitor to earth?
*At time t = 1 when button A is pressed and held down and the capacitor charges to +15V, does the voltage also travel through the line (like the electrons do), in the direction to the positive rail?
Pressing a pushbutton (A) allows current to flow from a 15V supply rail, via a 15kΩ resistor into an earthed 1mF capacitor.
The capacitor voltage Vc is monitored by a voltmeter, and can be reset to zero by means of another pushbutton (B).
Neatly sketch the circuit.
At time zero, button B is pressed.
At time t = 1 button A is pressed an held down
At time t = 3 button A is released.
At time t = 5 button B is pressed again.
Sketch a graph showing how the capacitor voltage varies over the period t = 0 to 6 seconds.
(Correct answer attached).
I am not sure of a couple of things:
*If both button A and B are held down at the same time, will there be 2 currents (one flowing into the capacitor, and the other following to B's earth line, simultaneously)?
*When the current flows through the capacitor to earth, howcome the current doesnt travel past the capacitor to earth?
*At time t = 1 when button A is pressed and held down and the capacitor charges to +15V, does the voltage also travel through the line (like the electrons do), in the direction to the positive rail?