Question

When a high resistance voltmeter is connected directly across a resistor, its
reading is 2 V. An electric cell is sending the current of 0.4 A measured by an
ammeter in the electric circuit in which a rheostat is also connected to vary the
current.
(a) Draw an equivalent labelled circuit for the given data.
(b) Find the resistance of the resistor.
(c) State the law applicable in the given case.
(d) Compare the resistance of voltmeter and ammeter.​

Answer 1

Answer:

Explanation:

Given that,

Voltmeter = 2 v

Current = 0.4 A

(I). We need to draw the circuit

When a high resistance voltmeter directly across a resistor. An electric cell is sending current in the circuit in which a rheostat is also connected.

(II). The law applicable is ohm's law

Ohm's law is defined as,

The current flowing through the conductor is directly proportional to the voltage difference.

In mathematically term

Where, V = potential difference

R = resistance

I = current

We draw the voltage -current graph

This graph shows the straight line.