two resistors are connected in series and then in parallel what effect will it have on the reading of voltmeter and ammeter why
Answers
two resistors are connected in series and then in parallel what effect will it have on the reading of voltmeter and ammeter why
Let say resistance = R
Voltage V & Current I
when they connected in series
total resistance Rs = R + R = 2R
Vs = Is * Rs
=> Vs = Is * 2R
Vs = voltage across both resistance together = V
=> V = Is * 2R
=> Is = V/2R = I/2
so current is halved. ammeter reading halved
V = IsR + IsR
V + IR/2 + IR/2
voltage measured across each resistance individually is halved
Voltage across both is same
When connected in Parallel
1/Rp = 1/R + 1/R
=> 1/Rp = 2/R
=> Rp = R/2
Vp = voltage across both resistance together = V
Vp = Ip * Rp
=> V = Ip * R/2
=> Ip = 2V/R
=> Ip = 2I
Current in total is doubled
Ip = V/R + V/R
Ip = I + I
Current in individual resistance = Same as earlier
Voltage across individual Resistance = Voltage across both resistance