How solve problems related to resistance

Asked by randhirsingh | 1st Jan, 2019, 06:36: PM

Expert Answer:

There are various formulae for determining the resistance.
The important formula is Ohm's law
which is V = IR
If values for voltage and current are known to us we can determine the resistance.
The other numericals which may be asked related to resistances is determining the equivalent resistance when the resistors are connected in series and parallel. 
For series combination,
Rs = R1 + R2 + .... Rn
where n - number of resistors connected in circuit in series combination
For parallel combination,
Rp = R1 + R2 + R3 + ....Rn 
where n - number of resistors connected in circuit in parallel combination
In numericals of combination of resistors, the resistors may be connected in series as well as parallel combination and you may be asked to determine the equivalent resistance in the given circuit. Solving such problems is easy provided you are able to determine which resistors are connected in series and how many are in parallel combination. Once you are able to determine this then the solving part of these type of numericals is easy as you just have to substitute the values in the formula. 
Remember that the resistors which are connected in series have only one end of it connected to one end of other resistor. Below diagram will help you to understand in better way.
When resistors are connected in parallel both end of one resistor is connected to both ends of one resistor or multiple resistors. 
Below diagram shows both the combination of resistors in series and parallel. 
Hope, this explanation would help you to solve the numericals. If you still have doubts regarding any numericals you can subscribe to and post your queries in Doubts and solutions section. And it's very important to keep practicing numericals and get an idea of various types of problems which may be asked in paper. Wish u all the best.

Answered by Shiwani Sawant | 2nd Jan, 2019, 12:06: PM