There are three main series of transistor codes used in the UK:The first letter B is for silicon, A is for germanium (rarely used now). The second letter indicates the type; for example C means low power audio frequency; D means high power audio frequency; F means low power high frequency. Read more about Transistor codes
Any linear bilateral circuit, which contain, G/R of same frequency the current that flows in any branch is the sum of the current's that would result from each G/R Working independently while other G/R.
First Law of Faraday's Electromagnetic Induction state that whenever a conductor are placed in a varying magnetic field emf are induced which is called induced emf, if the conductor circuit are closed current are also induced which is called induced current. Read more about Faraday's law's of Electromagnetic induction