Electromagnetism
Current Electricity
MCQ (Single Correct Answer)
Moving Charges and Magnetism
MCQ (Single Correct Answer)
Magnetism and Matter
MCQ (Single Correct Answer)
Electromagnetic Induction
MCQ (Single Correct Answer)
Alternating Current
MCQ (Single Correct Answer)
Electromagnetic Waves
MCQ (Single Correct Answer)
Modern Physics
Dual Nature of Radiation
MCQ (Single Correct Answer)
Semiconductor Devices and Logic Gates
MCQ (Single Correct Answer)
Communication Systems
MCQ (Single Correct Answer)
1
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

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

A
1.18 $$\times$$ 10$$^{-13}$$
B
1.28 $$\times$$ 10$$^{-13}$$
C
1.6 $$\times$$ 10$$^{-13}$$
D
1.72 $$\times$$ 10$$^{-13}$$
2
COMEDK 2020
MCQ (Single Correct Answer)
+1
-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?

A
1.2 $$\times$$ 10$$^{-5}$$ T, towards South
B
1.2 $$\times$$ 10$$^{-5}$$ T, towards North
C
1.2 $$\times$$ 10$$^{-5}$$ T, towards East
D
1.2 $$\times$$ 10$$^{-5}$$ T, towards West
3
COMEDK 2020
MCQ (Single Correct Answer)
+1
-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

A
24
B
35
C
60
D
54
4
COMEDK 2020
MCQ (Single Correct Answer)
+1
-0

The particle that cannot be accelerated by a cyclotron is

A
proton
B
$$\alpha$$-particle
C
electron
D
deuteron nucleus
COMEDK Subjects