A student measures the terminal potential difference (V) of a cell (of emf ε and internal resistance r) as a function of the current (I) flowing through it. The slope, and intercept, of the graph between V and I, then, respectively, equal

Question

A student measures the terminal potential difference (V) of a cell (of emf ε and internal resistance r) as a function of the current (I) flowing through it. The slope, and intercept, of the graph between V and I, then, respectively, equal (A) -r and ε  (B) r and -ε  (C) -ε and r (D) ε and -r

Tardigrade Admin · Accepted Answer

Given: A student measures the terminal potential difference

(V)

of a cell ( of emf

E

and internal resistance

r

) as a function of the current

(I)

flowing through it.
To find the slope and intercept of the graph between

V

and I
Solution:
The general equation of

EMF

in cell:

V = E - i r

\Rightarrow V = E + i (- r)

Compare it with standard equation of the line:

y = m x + c

\Rightarrow y = c + m x

Since graph of student is

V

vs

I

∴, V

is

y

and

I

is

x

Therefore,

E

is intercept and

(- r)

is slope

Q. A student measures the terminal potential difference $(V)$ of a cell (of emf $ε$ and internal resistance $r$ ) as a function of the current $(I)$ flowing through it. The slope, and intercept, of the graph between $V$ and $I$ , then, respectively, equal

$- r$ and $ε$

$r$ and $- ε$

$- ε$ and $r$

$ε$ and $- r$

Q. A student measures the terminal potential difference (V) of a cell (of emf ε and internal resistance r) as a function of the current (I) flowing through it. The slope, and intercept, of the graph between V and I, then, respectively, equal

−r and ε

r and −ε

−ε and r

ε and −r

Q. A student measures the terminal potential difference $(V)$ of a cell (of emf $ε$ and internal resistance $r$ ) as a function of the current $(I)$ flowing through it. The slope, and intercept, of the graph between $V$ and $I$ , then, respectively, equal

$- r$ and $ε$

$r$ and $- ε$

$- ε$ and $r$

$ε$ and $- r$