How is resistance calculeate (write the formula) and list three things that can increase it.?

Question

Thanks

Answer 1

Resistance is found by transposing ohm's law;

R =  V/I

You divide Voltage by the Current to get Resistance.

You can increase resistance by;

1) Adding more resistors

2) Adding more resistors in series

3) Putting more load on the circuit (more appliances)

Answer 2

resistivity of the material is based on a few seperate values.

the formula is :

R= (P*L)/A

where

R=resistance

P=static resistivity of the material

L=length of material section

A=cross section of the material

So if you want to increase the resistance of an object

1. lengthen the section of the object

2. decrease the cross sectional area

3. choose a different material with a higher resistivity

4.Temperature can effect resistance also, for metals it tends to increase, and semi-conductors it tends to decrease the resistivity

Answer 3

Resistance is calculated using the simple ohms law equation

R = V/I

R is the symbol for resistance measured in ohms

V is the symbol for voltage measured in Volts

I is the symbol for current measured in Amperes

To calculate any of the above values for a given circuit the other 2 must be known.

Eg. a 6 Volt light bulb draws 2 Amps of current what is the resistance of the light bulb

R = V/I = 6/2 = 3 ohms.

The resitance of any material depends on its physical characteristics

Its Cross sectional area, Its length and its temperature

To increase resistance REDUCE the cross sectional area

To increase resistance INCREASE the length

And for most materials (not all) to increase the resistance increase its temperature