Electronics Engineering (ELEX) Board Practice Exam

Which circuit is utilized to shift the DC level of a signal without altering its waveform?

1. Clamper

2. Clipper

3. Filter

4. Integrator

The correct answer is: Clamper

The circuit that is utilized to shift the DC level of a signal without altering its waveform is the clamper. A clamper works by changing the DC level of a signal while preserving the shape of the waveform. This is achieved through the use of diodes and capacitors, which charge and discharge to add or subtract a DC voltage from the input signal. When the clamper circuit is applied, it effectively 'clamps' the voltage of the waveform to a new level, thus translating it either upwards or downwards on the voltage scale without altering the frequency content or the waveform shape. This is particularly useful in applications where level shifting is required, such as when interfacing different voltage level systems or conditioning signals for further processing. In contrast, other options serve different purposes: the clipper removes portions of the waveform above or below certain voltage levels, which changes the shape; the filter alters the frequency components of a signal, affecting its overall waveform; and the integrator produces an output that is the integral of the input signal, significantly modifying the waveform shape.