Statement (I) : A uniform electric field and a uniform magnetic field are pointed in the same direction. If an electron is projected in the same direction the electron velocity will decrease in magnitude. Statement (II) : Two infinite long parallel wires are carrying current in the same direction. The magnetic field at a point midway between the wires is zero. Statement (III) : No net force acts on a rectangular coil carrying a steady current when suspended in a uniform magnetic field. Which of the following is correct?

• Correct answer
  A

  Statements I, II and III are true.
• B

  Statements I and II are true, but statement III is false.
• C

  Statements II and III are true, but statement I is false.
• D

  Statements I and III are true, but statement II is false.

Solution

$\overrightarrow{\mathrm{B}}$ will not effect electron and $\overrightarrow{\mathrm{E}}$ will reduce electron velocity as electric field on it is in direction opposite to field. So (I) is correct
$$ \overrightarrow{\mathrm{B}}_{\text {net }}=\frac{\mu_0 \mathrm{i}}{2 \pi \mathrm{r}} \otimes+\frac{\mu_0 \mathrm{i}}{2 \pi \mathrm{r}} \odot=0 $$ So, (II) is correct No net force acts on rectangular loop placed in magnetic field. So (III) is correct.

Hence, the correct answer is option: 'A'.