Question

The table below shows reading noted in an ohm’s law verification experiment. Fill in the blanks with suitable reading.

V	I	R
1V	1mA	--
2V	--	$1k\Omega$
--	3mA	$1k\Omega$
4V	4mA	--

Answer 1

We are given four sets of observations of the Ohm’s law experiment. In order to complete the table and solve this problem, we must have prior knowledge of Ohm’s law and must be well aware of its fundamentals. In each reading, any one out of the three quantities is missing. Hence, we shall apply the Ohm’s law and find the missing value in the readings taking each one of them one by one.

Complete answer:
According to Ohm’s law, voltage equals current times resistance.
$\Rightarrow V=IR$ …………… equation (1)
Thus, we shall use this relation to find the missing current, voltage or resistance in the given readings.
In the first reading, given that $V=1V$ and $I=1mA=1\times {{10}^{-3}}A$
Here, we have to find the resistance in the circuit.
Using equation (1) with the data provided to us, we get
$1={{10}^{-3}}\left( R \right)$
Dividing ${{10}^{-{{3}^{{}}}}}$on both sides to find R, we get
$\Rightarrow R={{10}^{3}}\Omega$
$\therefore R=1k\Omega$
In the second reading, given that $V=2V$ and $R=1k\Omega =1\times {{10}^{3}}\Omega$
Here, we have to find the current in the circuit.
Using equation (1) with the data provided to us, we get
$2=\left( I \right){{10}^{3}}$
Dividing ${{10}^{3}}$on both sides to find I, we get
$\begin{aligned} & \Rightarrow I=\dfrac{2}{{{10}^{3}}}A \\\ & \Rightarrow I=2\times {{10}^{-3}}A \\\ \end{aligned}$
$\therefore I=2mA$
In the third reading, given that $I=3mA$ and $R=1k\Omega =1\times {{10}^{3}}\Omega$
Here, we have to find the voltage in the circuit.
Using equation (1) with the data provided to us, we get
$V=\left( 3\times {{10}^{-3}} \right){{10}^{3}}$
$\Rightarrow V=3V$
In the fourth reading, given that $V=4V$ and $I=4mA=4\times {{10}^{-3}}A$
Here, we have to find the resistance in the circuit.
Using equation (1) with the data provided to us, we get
$4=4\times {{10}^{-3}}\left( R \right)$
Cancelling 4 from both sides to find R, we get
$\Rightarrow R={{10}^{3}}\Omega$
$\therefore R=1k\Omega$

V	I	R
1V	1mA	$1k\Omega$
2V	2mA	$1k\Omega$
3V	3mA	$1k\Omega$
4V	4mA	$1k\Omega$

Note:
Ohm’s law is designed to give the relation between the resistance $\left( R \right)$ , current $\left( I \right)$ and voltage $\left( V \right)$ across a resistor in an electric circuit. It is the most fundamental law related to electric circuits. Resistance connects or relates the voltage and current in a circuit to each other.