Electrical Engineering - Series-Parallel Circuits - Discussion

By ohms law we know that current is directly proportional to voltage and inversely proportional to resistance. Adding load means adding resistance we all know that when resistance is high, current is low when resistance is low current is high.

So here resistance is low means current is high which is directly proportional to voltage so answer is max in given options 1000 is max.

When voltage increase current is decrease so answer d is correct because it is highest voltage in given option.

It is given that in which of the following options voltmeter presents a minimum load means here the voltmeter is behaving as a load. For more and more voltages the coil in the voltmeter has low value.

For example take a voltage divider. If the voltage setting is less than full voltage appears across the load.

In the same way when coil resistance is low full voltage will be appeared across load that means the voltmeter is not much acting as a load. So 1000v is correct. If in options any value which is given more than that then it will be correct.

Consider formula P = V*I hence V is inversely proportional to current while load consideration.

Anybody can tell me V=IR then how voltage is inversely proportional to current?

Voltage increase means current decrease. So load depends on current. minimum Current means load also minimum.

@All.

A voltmeter's setting is made in terms of Ohm/V.

So, for sensitive circuits, the voltmeter will draw minimum current when its resistance is maximum which will be for V=1000V available in options.

For example, if Voltmeter sensitivity is 1000 Ohm/V then for 1000 Volt, its resistance will be 1000 * 1000 = 1000000 Ohm and it will draw negligible current.
That's it.

Voltage increase means current decrease. So load depends on current. Current decrease so load also minimum.

Voltage is inversely proportional to load on the system-i.e as load increases voltage decreases due to v-drops hence they are inversely related. So minimum load pertains to maximum voltage among the given options.