Question

Find the potential difference between the point if 20 mj work is done in moving a charge of 100 uc across two points in an electric circuit​

Answer 1

GIVEN:

• Work done (W) = 20 MJ
• Charge (q) = 100 UC

TO FIND:

• Potential difference (V)

SOLUTION:

We have,

• Work done = 20 MJ

We know,

• 1 MJ = 10⁶ J

So,

• 20 MJ = 20 × 10⁶ J
• 20 × 10⁷ J

We have,

• Charge = 100 uc

We know,

• 1 uc = 10⁻⁶ C

So,

• 100 uc = 100 × 10⁻⁶ C
• 10⁻⁴ C

Now using the formula,

• V = W/Q

Where,

• V = Potential difference
• W = Work done
• Q = Charge

Substituting we get,

• V = 20 × 10⁷ J/10⁻⁴ C
• V = 20 × 10³
• V = 2000 V

ANSWER:

• The potential difference across the two points in the electric circuit is 2000 V.

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Answer 2

By the definition of potential difference we have,

∆V = W/q

W = 20 mJ

= 20 × 10-³ J

(as, m means Mili which means 10-³)

q = 100 μC

= 100 × 10-⁶C

(μ = 10-⁶)

= 10-⁴ C

Hence,

∆V = 20 × 10-³/10-⁴

= 20 × 10

= 200 V