30 ohms

## What happens to the current across a circuit when the voltage is doubled while the resistance is held constant?

The current is directly proportional to the voltage and inversely proportional to the resistance. So doubling or tripling the resistance will cause the current to be one-half or one-third the original value.

## What is the effect on the current in a wire if both the voltage and resistance are doubled?

What is the effect on the current in a wire if both the voltage across it and its resistance are doubled? The current is doubled. The current is halved.

## What happens to the power consumption of a circuit as its resistance increases?

The power dissipated in a resistor is given by P = V2/R which means power decreases if resistance increases. Yet this power is also given by P = I2R, which means power increases if resistance increases.

## What happens if you increase the voltage in a circuit?

The relationship between Voltage, Current and Resistance forms the basis of Ohm’s law. In a linear circuit of fixed resistance, if we increase the voltage, the current goes up, and similarly, if we decrease the voltage, the current goes down.

## Is voltage affected by resistance?

Ohm’s law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R).

## What is the resistance of an ideal galvanometer?

An ideal galvanometer or ammeter has zero resistance since in this case the meter will not affect the resistance of the circuit for which we wish to measure the current. However, it is not possible for any meter to have zero resistance under normal operating conditions.

## What is the resistance of an ammeter?

The resistance of an ammeter is very small and for an ideal ammeter, its value is zero

## What should be the resistance of ammeter and voltmeter?

Resistance of an ideal voltmeter is Infinite and that of an ammeter is zero.

## Why should a voltmeter have high resistance?

A voltmeter measures the voltage difference between the two different points (say, on different sides of a resistor), but it should not change the amount of current going through the element between these two points. So it should have very high resistance so mat it doesn’t draw current through it.

## What should be the resistance of an ideal ammeter and why?

An ideal ammeter should have zero resistance. It is connected in series to measure current . So it should not add any resistance to the circuit. Otherwise the current in the circuit is modified by adding ammeter.

## Why do ammeters burn when connected in parallel?

An ammeter has very low resistance, so if connected in parallel, it draws a very high current nd thus it burns out

## Why voltmeter should be connected in parallel?

In order for a voltmeter to measure a device’s voltage, it must be connected in parallel to that device. This is necessary because objects in parallel experience the same potential difference.

## What will happen if the position of ammeter and voltmeter are interchanged?

The voltmeter is a high resistance device used to measure voltage across two point and it is always connected in parallel with the the circuit. If the positions of these two are interchanged, the ammeter will be destroyed by high amount of current given that it is of low resistance