Correct Answer: Readings recorded by P₃ person are incorrect

Explanation

Power of the convex lens is given as +5 D.

Focal length f is given by

f = 1 / P = 1 / 5 m = 0.2 m = 20 cm

For a convex lens, the lens formula is

1/f = 1/v + 1/u

Now check readings of each person.

For P₁: u = 25 cm, v = 96 cm

1/v + 1/u = 1/96 + 1/25

= (25 + 96) / 2400

= 121 / 2400 ≈ 1/19.8

This is approximately equal to 1/20, hence P₁ is correct.

For P₂: u = 30 cm, v = 62 cm

1/v + 1/u = 1/62 + 1/30

= (30 + 62) / 1860

= 92 / 1860 ≈ 1/20.2

Approximately equal to 1/20, hence P₂ is correct.

For P₃: u = 35 cm, v = 37 cm

1/v + 1/u = 1/37 + 1/35

= (35 + 37) / 1295

= 72 / 1295 ≈ 1/18

This does not match 1/20, hence P₃ is incorrect.

For P₄: u = 45 cm, v = 35 cm

1/v + 1/u = 1/35 + 1/45

= (45 + 35) / 1575

= 80 / 1575 ≈ 1/19.7

Approximately equal to 1/20, hence P₄ is correct.

For P₅: u = 50 cm, v = 32 cm

1/v + 1/u = 1/32 + 1/50

= (50 + 32) / 1600

= 82 / 1600 ≈ 1/19.5

Approximately equal to 1/20, hence P₅ is correct.

Therefore, only the readings recorded by P₃ are incorrect.

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