A particle of mass 10-3 kg and charge 5 μ C is thrown at a speed of 20 m s-1 against a uniform electric field of strength 2 × 105 N C-1. The distance travelled by particle before coming to rest is

Question

A particle of mass 10-3 kg and charge 5 μ C is thrown at a speed of 20 m s-1 against a uniform electric field of strength 2 × 105 N C-1. The distance travelled by particle before coming to rest is (A) 0.1 m (B) 0.2 m (C) 0.3 m (D) 0.4 m

Tardigrade Admin · Accepted Answer

F=qE=5×10-6×2×105=1 N Since, the particle is thrown against the field ∴ a=-F/m=-(1/10-3)=-103 m s-2 As v2-u2=2as ∴ 02-(20)2=2×(-10)3× s or s=0.2 m

Q. A particle of mass $1 0^{- 3} k g$ and charge $5 μ C$ is thrown at a speed of $20 m s^{- 1}$ against a uniform electric field of strength $2 \times 1 0^{5} N C^{- 1}$ . The distance travelled by particle before coming to rest is

$0.1 m$

$0.2 m$

$0.3 m$

$0.4 m$

$F = qE = 5 \times 1 0^{- 6} \times 2 \times 1 0^{5} = 1 N$
Since, the particle is thrown against the field
$∴ a = - F / m = - \frac{1}{1 0 ^{- 3}} = - 1 0^{3} m s^{- 2}$
As $v^{2} - u^{2} = 2 a s$
$∴ 0^{2} - (20)^{2} = 2 \times (- 10)^{3} \times s$
or $s = 0.2 m$

Q. A particle of mass 10−3kg and charge 5μC is thrown at a speed of 20ms−1 against a uniform electric field of strength 2×105NC−1. The distance travelled by particle before coming to rest is

0.1m

0.2m

0.3m

0.4m