Why are resistance connected in series ?

Why are resistance connected in parallel?

A lamp and a resistance are connected in series to a 220 V d.c. source. What will happen to glow of the lamp, when same combination is connected to a 220 V - 50 Hz a.c. supply?

Find the equivalent of resistances of the individual resistance connected in series?

What is the need of combining different resistors? What is the resultant resistance when number of resistances are connected in series?

A resistor of 5Omega resistance is connected in series with a paralel combination of a number of resis-tors each of 6Omega . If the total resistance of the combination is 7Omega , how many resistors are in parallel?

A galvanometer of resistance G is converted into a voltmeter to measure upto V volts by connecting a resistance R_1 in series with the coil. If a resistance R_2 s connected in series with it then it can measure upto V/2 volts Find the resistance R, in terms of R_1 and R_2 required to convert it into a voltmeter that can read upto 2V volts.

n cells of e.m.f E and internal resistance r are connected in series with an external resistance R . the current will increase n times that of a single cell, if