## Posts

Showing posts from August, 2024

### Combination of cell in the circuit

A.) Combination of cells when emf of cells are same: There are three types of combinations of cells in the circuit 1.) Series Combination of Cells 2.) Parallel Combination of Cells 3.) Mixed Combination of Cells 1.) Series Combination of Cells: Let us consider that the $n$ - cells having emf (electromotive force) $E$ and internal resistance $r$ are connected in series with external resistance $R$. Then from the figure given below The total emf of the $n$ - cell = $nE$ The total internal resistance of the $n$ - cell = $nr$ The total resistance of the circuit = $nr+R$ The total current in the circuit $i=\frac{Total \: emf \: of \: the \: n - series \: cell}{Total \: resistance \: of \: the \: circuit}$ $i=\frac{nE}{nr+R}$ 2.) Parallel Combination of Cells: Let us consider that the $n$ - cells having emf (electromotive force) $E$ and internal resistance $r$ are connected in parallel with external resistance $R$. Then from the figure given below The t

### Relation between electromotive force (E), internal resistance (r) and potential difference (V) in a circuit

Relation between electromotive force $(E)$, internal resistance $(r)$ and potential difference $(V)$: Let us consider: The cell having electro-motive force = $E$ The cell having internal resistance = $r$ The external resistance of the circuit = $R$ The potential difference between the external resistance of the circuit = $V$ The current in circuit = $i$ So, The emf of the cell from the given circuit in the figure above $E=iR+ir$ $E = V+ir$ $V=E-ir$

### Resolving Power of Optical Instrument | Rayleigh Criterion of Resolution

Resolving power of an optical instrument: The ability of an optical instrument to just resolve the images of two closely spaced objects is called its resolving power. Limit of Resolution: The smallest distance between two closely spaced objects that can be seen as separated or just separated from each other through an optical instrument is known as the limit of resolution of that optical instrument. Rayleigh Criterion: Rayleigh criterion describes the separation between the two objects or wavelengths (i.e. resolving power) by the resultant intensity distribution of objects and wavelengths. According to Rayleigh's criterion, there are the following cases: Case:1 If two point sources have very small angular separation, then central or principal maxima in their diffraction patterns will overlap to a large extent and resultant intensity shows uniform variation. As shown in the figure below. In this case, the two objects or wavelengths can not be distinguished or