Question

1. An electron enters a chamber in which a uniform
magnetic field is present as shown.
Magnetic field
An electric field of appropriate magnitude is also applied
so that the electron travels undeviated without any change
in its speed through the chamber. We are ignoring gravity.
Then, the direction of the electric field is
(1) opposite to the direction of the magnetic field
(2) opposite to the direction of the electron's motion
(3) normal to the plane of the paper and coming out of
the plane of the paper
(4) normal to the plane of the paper and into the plane
of the paper
​

Answer 1

charge of electron is negative.

Now electric force on electron will be opposite to the direction of electric field. Hence the Electric field should be normal to plane of paper and into the paper