Bounded Signal is a signal which is having a finite value at all instants of time. Consider a continuous-time signal x(t) such that x(t) has finite-amplitude (value) at all time (t) as shown in figure 1 is an example of the bounded signal. Examples of bounded signals are sin(t), cos(t), u(t). All these three signals … Read more
A system is said to be causal system if its output at all the instants depends on the past value and/or present value of the input. A system is said to be a non-causal system if its output at any instant depends on the future value of the input. Consider the following system. x(t) is … Read more
Maxwell inductance bridge is an AC bridge used for measurement of inductance of a coil by comparison with a variable standard self-inductance. Maxwell inductance bridge is shown in figure 1 under balance condition. Under balance condition, the current (Id) through the detector is zero. Hence current through arm ab and arm cd is the same. … Read more
AC Bridges are those circuits which are used for the measurement of unknown resistances, capacitance, inductance, frequency and mutual inductance. AC bridges operate with only an AC source. These bridges are very convenient and give the accurate result of the measurement. The construction of these bridge is very simple. Figure 1 shows an AC bridge. … Read more
Ionization type Vacuum gauge is a device which is used for the measurement of pressure in vacuum systems or in the very low-pressure region (below atmospheric pressure). It can measure pressure from 10-3 to 10-8 mm of Hg. Figure 1 shows the ionization type vacuum gauge. The gauge consists of 3 electrodes i.e. cathode (heating filament), grid and … Read more
Magnetic field intensity is defined as the degree to which the magnetising field can magnetise a material. The magnetic field which magnetises a material placed in it is known as the magnetising field. Magnetic field intensity is denoted by ‘H‘ and also known as intensity of magnetising field or magnetising force. Magnetic field intensity (H) … Read more
Magnetic permeability is defined as the power of conducting magnetic lines of force by a substance. It is denoted by ‘μ‘ (mu). Magnetic permeability of a substance is equal to the ratio of the magnitude of magnetic flux density (B) to the magnitude of magnetic field intensity (H). The SI unit of Magnetic permeability is … Read more
Magnetic flux density is defined as the number of magnetic lines of force passing normally through a unit area of a substance. It is denoted by B. The S.I. unit of magnetic flux density is Tesla (T). It is a vector quantity. The CGS unit of magnetic flux density is gauss (G). Consider a surface … Read more
Magnetic flux is defined as the number of magnetic lines of force passing normally through a surface. It is denoted by symbol Φ (phi). The S.I. unit of magnetic flux is weber (Wb). It is a scalar quantity. The CGS unit of magnetic flux is maxwell. Consider a surface having area, A in the magnetic … Read more
A magnetic field is a space around a magnet or a current-carrying wire within which its magnetic effects can be experienced. The magnetic effects are commonly seen in permanent magnets, electromagnets, etc. These magnets can pull or attract magnetic materials like iron and attract or repel other magnets due to its magnetic field. A magnetic … Read more