Tricky questions

## Electrostatic Potential And Capacitance

- Some questions are often misinterpreted by the students. Let's explore them!
1

### Relation between potential and electric field

As we know electric field is related to potential with equation (). If equation of potential surface is varies with x,y, and z then electric field at any point is calculated by using concepts of partial differentiation.
2

### Capacitor with dielectric slab

When you induce a dielectric material inside the capacitor then the capacitance of the capacitor will increase but when the thickness of plate is less than the distance between the plates then overall capacitance decrease. Also when you increase the distance between the plate, the capacitance of the capacitor decrease. Lets practice this question.
3

### Arrangement of Identical metal plates in air

When the number of identical plates arranged in the air, this arrangement can act as a capacitor. To calculate the capacitance of arrangement of these capacitors, connect a battery about the given terminal point and try to identify the same potential point. Once you identify the potential of all plates then rearrange these plates by connection same potential plets. This arrangement will give you definite patterns like series, Parallel or mixed combination of capacitors. Let's practise this question.
4

### Force on dielectric slab

When you keep a dielectric slab near a capacitor, Dielectric slab experiences force. This force try to pull the slab inside the capacitor. If you keep battery connected during this process, Potential difference across capacitor would be constant. Force on the dielectric slab can be calculated by differentiating energy equation after inserting slab by 'x' distance.
5

### Equivalent capacitance

During calculation of capacitance of number of capacitors that are added in the circuit, we need to take care of few points like patterns of symmetry, Same potential points. When you found same potential point then rearrange all capacitors and joint all same potential point together. Let's practice this question.
6

### Dielectric constant of material

When you keep the conducting material inside the electric field then electric field inside the material would be zero. Lets think about dielectric constant of conducting materials.
7

### Energy stored between two spherical shells

Energy stored between two charged concentric shells can be calculated by assuming arrangement as a spherical capacitor of capacitance 'C'. If potential difference between to two shells is 'v' then we can write energy store