MCQ
1 electron volt = __________ J.
  • A
    1.6 × 10-19
  • B
    4.8 × 10-19
  • C
    1.6 × 10-10
  • D
    10

Answer

  1. 1.6 × 10-19

Explanation:

1 electron volt is the amount of work done if an electron is passed through a potential difference of 1V. Therefore the work done = 1V × charge of an electron = 1.602 × 10-19 J. But it is a small quantity and hence we use kilo electron volt and mega electron volt in practical.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Which of the following theories is the most satisfactory about the origin of the universe

(a) Big Bang theory

(b) Pulsating theory

(c) Steady state theory

(d)  None of these

A proton of mass m and charge +e is moving in a circular orbit in a magnetic field with energy 1 MeV. What should be the energy of α -  particle (mass = 4m and charge = + 2e), so that it can revolve in the path of same radius

(a) 1 MeV

(b) 4 MeV

(c) 2 MeV

(d) 0.5 MeV

Consider the following statements and select the correct statement(s).
  1. Electric field lines are always perpendicular to equipotential surface.
  2. No two equipotential surfaces can intersect each other.
  3. Electric field lines are in the direction of tangent to an equipotential surface.

    X-rays are

    (a) Stream of electrons

    (b) Stream of positively charged particles

    (c) Electromagnetic radiations of high frequency

    (d) Stream of uncharged particles

    A neutron exerts a force on a proton which is:
    1. Gravitational.
    2. Electromagnetic.
    3. Nuclear.
    4. Weak.
    A moving coil galvanometer is based on the:

    20 μA current flows for 30 seconds in a wire, transfer of charge will be

    (a) 2

    (b) 4

    (c) 6

    (d) 8

    A convex lens forms a real image of a point object placed on its principal axis. If the upper half of the lens is painted black:

    Assertion  :   Current is passed through a metallic wire, heating it red. When cold water is poured on half of its portion, then rest of the half portion become more hot.  

    Reason    : Resistances decreases due to decrease in temperature and so current through wire increases.

    (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

    (b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

    (c) If assertion is true but reason is false.

    (d) If the assertion and reason both are false.

    PQRS is a square loop made of uniform conducting wire the current enters the loop at P and leaves at S.  Then the magnetic field will be

    (a) Maximum at the centre of the loop

    (b) Zero at the centre of loop

    (c) Zero at all points inside the loop

    (d) Zero at all points outside of the loop