A high Q requires imaginary numbers, and because they are imaginary, such circuits are not real.

A selective filter requires a high Q, which corresponds to a narrow bandwidth. In a series RLC circuit, Q is inversely proportional to R. Therefore, R should be minimised for high selectivity.

A high Q factor leads to a wide bandwidth, which is ideal for filtering. Q is maximised by setting L = C, as R has no effect on Q, only on the resonant frequency.

A high Q factor is desirable for a selective filter and can be implemented by maximising the resistance R. A high Q results in a wide bandwidth.

The Q factor is defined as the ratio of bandwidth to resonant frequency ( Q = BW / ). A selective filter requires a low Q, which is achieved with a low resistance R.

The Q factor is defined as Q = /BW. A high Q (i.e., narrow bandwidth) is achieved by increasing R, since the resonant frequency is directly proportional to R.

The bandwidth is independent of Q factor and is only set by R. The Q factor is set only by L and C. A selective filter should have a low R, and a high .