COMEDK 2020 | Moving Charges and Magnetism Question 20 | Physics

An electron moves with speed of 2 $$\times$$ 10$$^5$$ m/s along the positive x-direction in a magnetic field $$B = (\widehat i - 4\widehat j - 3\widehat k)\,T$$. The magnitude of the force (in N) experienced by the electron is

1.18 $$\times$$ 10$$^{-13}$$

1.28 $$\times$$ 10$$^{-13}$$

1.6 $$\times$$ 10$$^{-13}$$

1.72 $$\times$$ 10$$^{-13}$$

COMEDK 2020

MCQ (Single Correct Answer)

-0

A horizontal overhead power line carries a current of 90 A in East to West direction. What is the magnitude and direction of the magnetic field due to the current, 1.5 m below the line?

1.2 $$\times$$ 10$$^{-5}$$ T, towards South

1.2 $$\times$$ 10$$^{-5}$$ T, towards North

1.2 $$\times$$ 10$$^{-5}$$ T, towards East

1.2 $$\times$$ 10$$^{-5}$$ T, towards West

COMEDK 2020

MCQ (Single Correct Answer)

-0

A moving coil galvanometer has 28 turns and area of coil is $$4\times 10^{-2}$$ m$$^2$$. If the magnetic field is 0.2 T, then to increase the sensitivity by 25% without changing area and field, the number of turns should be changed to

COMEDK 2020

MCQ (Single Correct Answer)

-0

The particle that cannot be accelerated by a cyclotron is

proton

$$\alpha$$-particle

electron

deuteron nucleus

COMEDK Subjects