Question

Two points $A$ and $B$ are maintained at the potentials of $18 V$ and $-5 V$ respectively. What will be the work done in moving $150 \alpha$ -particles from $A$ to $B$ ?

• A. $4 \times 10^{-12} J$
• B. $8 \times 10^{-8} J$
• C. $2 \times 10^{-15} J$
• D. $1.1 \times 10^{-15} J$

Answer 1

Answer: (D)

$W = q \Delta V$
$W =150 \times e \left( V _{ B }- V _{ A }\right)$
$ \therefore W=150 \times 2 \times 1.6 \times 10^{-19}(-5-18)$
$W =11040 \times 10^{-19} J$
$W =1.1 \times 10^{-15}\, J $