Question

The plot represents the flow of current through a wire at three different times. The ratio of charges flowing through the wire at different times is

• A. $2:1:2$
• B. $1:3:3$
• C. $1:1:1$
• D. $2:3:4$

Answer 1

The correct option is C $1:1:1$

$\text{Step 1: Area under graph}$

We know that $q=\int i\times dt$

So, charge flowing through wire equals the area under curve of $I-t$ graph

In 1st case Area $=base\times height=1\times 2=2$

So, $q_1=2C$

In 2nd case , Area $=base\times height=2\times 1=2$

So, $q_2=2C$

In 3rd case Area $=\frac{1}{2}\times base\times height=\frac{1}{2}\times 2\times 2=2$

So, $q_3=2C$

$\text{Step 2: Ratio of charges}$

$q_1:q_2:q_3$ $=1:1:1$

Hence, Option C is correct