A plane electromagnetic wave of intensity of 10 W / m 2 strikes a small mirror of area 20 cm 2, held perpendicular to the approaching wave. The radiation force on the mirror will be

Question

A plane electromagnetic wave of intensity of 10 W / m 2 strikes a small mirror of area 20 cm 2, held perpendicular to the approaching wave. The radiation force on the mirror will be (A) 6.6 × 10-11 N (B) 1.33 × 10-11 N (C) 1.33 × 10-10 N (D) 6.6 × 10-10 N

Tardigrade Admin · Accepted Answer

Radiation force = momentum transferred per second by electromagnetic wave to the mirror =(2 Sa v A/c)=(2 ×(10) ×(20 × 10-4)/(3 × 108)) =1.33 × 10-10 N

Q. A plane electromagnetic wave of intensity of $10 W / m^{2}$ strikes a small mirror of area $20 c m^{2}$ , held perpendicular to the approaching wave. The radiation force on the mirror will be

$6.6 \times 1 0^{- 11} N$

$1.33 \times 1 0^{- 11} N$

$1.33 \times 1 0^{- 10} N$

$6.6 \times 1 0^{- 10} N$

Radiation force = momentum transferred per second by electromagnetic wave to the mirror
$= \frac{2 S _{a v} A}{c} = \frac{2 \times ( 10 ) \times ( 20 \times 1 0 ^{- 4} )}{( 3 \times 1 0 ^{8} )}$
$= 1.33 \times 1 0^{- 10} N$

Q. A plane electromagnetic wave of intensity of 10W/m2 strikes a small mirror of area 20cm2, held perpendicular to the approaching wave. The radiation force on the mirror will be

6.6×10−11N

1.33×10−11N

1.33×10−10N

6.6×10−10N