Question

Which of the following symbols are used for current generating sources?
A)

B)

C)

D) $ {\text{None of the above.}}$

Answer 1

Hint: A current source is an active circuit feature that provides a constant current to a circuit irrespective of the voltage that develops through its terminals.

Complete solution:
As their name means, the current source is a circuit element that retains a constant current flux regardless of the voltage produced through its terminals while other circuit elements decide the voltage. This means that an ideal constant current source supplies a certain amount of current constantly regardless of the impedance that it drives and, as such, an ideal current source could potentially provide an unlimited quantity of electricity.
Ideal constant current sources are represented similarly to the voltage sources, except this time a circle with an arrow within is the current source symbolising the current flow direction. The current orientation is the polarity of the related voltage, which flows out of the positive terminal.
Ideal independent current references for circuit theorems and circuit analyses methods for circuits that contain actual active elements are usually used. A resistor in series, with voltage sources that generate currents from a few milli-ampere to several hundreds of amperes, is the simplest type of a current source.
 A is symbol of voltage source
 B is a symbol used for current generating sources and C is a symbol of a transformer.
Therefore, B is the correct option.

Note: In particular where there are other voltage or current sources in the connected circuit, it can be difficult to evaluate the size and polarity of the voltage of an ideal current source relative to the current.
However, if the only source in the circuit is the current source, the polarity of the voltage is easier to ascertain around the source. If, however, there are more than one source, the voltage of a terminal depends on the linked network.