Engineering Entrance Sample Papers

Magnetic Effect of Current Important Questions Magnetic effect of current and Magnetism objective type questions with answers.

Magnetic Effect of Current and Magnetism (Physics)

 Question 1
If a long hollow copper pipe carries a direct current, the magnetic field associated with the current will be
 A Only inside the pipe B Only outside the pipe C Both inside and outside the pipe D Neither inside nor outside the pipe
 Question 2
A charged particle moving in a magnetic field experiences a resultant force
 A In the direction of field B In the direction opposite to that field C None of these D In the direction perpendicular to both the field and its velocity
 Question 3
An electron moving towards the east enters a magnetic field directed towards the north. The force on the electron will be directed
 A Vertically downward B Towards the south C Towards the west D Vertically upward
 Question 4
A beam of electrons and protons move parallel to each other in the same direction, then they
 A Repel each other B No relation C Neither attract nor repel D Attract each other
 Question 5
An electron moving with a uniform velocity along the positive x-direction enters a magnetic field directed along the positive y-direction. The force on the electron is directed along
 A Positive y-direction B Negative z-direction C Positive z-direction D Negative y-direction
 Question 6
A moving coil sensitive galvanometer gives at once much more deflection. To control its speed of deflection
 A A magnet should be placed near the coil B A high resistance is to be connected across its terminals C The body of galvanometer should be earthed D A small copper wire should be connected across its terminals
 Question 7
One proton beam enters a magnetic field of 10–4T normally, Specific charge = 1011 C/kg velocity = 107 m/s. What is the radius of the circle described by it
 A 10 m B None of these C 0.1 m D 1 m
 Question 8
A charge + Q is moving upwards vertically. It enters a magnetic field directed to the north. The force on the charge will be towards
 A East B South C North D West
 Question 9
A stream of electrons is projected horizontally to the right. A straight conductor carrying a current is supported parallel to electron stream and above it. If the current in the conductor is from left to right then what will be the effect on electron stream
 A The electron stream will be pulled downward B The electron stream will be pulled upward C The electron stream will be retarted D The electron beam will be speeded up towards the right
 Question 10
A small cylindrical soft iron piece is kept in a galvanometer so that
 A A uniform magnetic field is produced B There is a steady deflection of the coil C All of these D A radial uniform magnetic field is produced
 Question 11
“On flowing current in a conducting wire the magnetic field produces around it.” It is a law of
 A Ampere B Lenz C Ohm D Maxwell
 Question 12
If two streams of protons move parallel to each other in the same direction, then they
 A Do not exert any force on each other B Get rotated to be perpendicular to each other C Repel each other D Attract each other
 Question 13
A current flows in a conductor from east to west. The direction of the magnetic field at a points above the conductor is ..
 A Towards west B Towards east C Towards south D Towards north
 Question 14
Two straight horizontal parallel wires are carrying the same current in the same direction, d is the distance between the wires. You are provided with a small freely suspended magnetic needle. At which of the following positions will the orientation of the needle be independent of the magnitude of the current in the wires
 A At a distance d/2 from any of the wires in the horizontal plane B At a distance d/2 from any of the wires C Anywhere on the circumference of a vertical circle of radius d and centre halfway between the wires D At points halfway between the wires in the horizontal plane
 Question 15
The magnetic field at a distance r from a long wire carrying current i is 0.4 Tesla. The magnetic field at a distance 2r is
 A 0.2 Tesla B 0.1 Tesla C 1.6 Tesla D 0.8 Tesla
 Question 16
A charged particle enters a magnetic field H with its initial velocity making an angle of 45o with H. The path of the particle will be
 A An ellipse B A straight line C A circle D A helix
 Question 17
A wire carrying current I and other carrying 2I in the same direction produces a magnetic field B at the mid point. What will be the field when 2I wire is switched off
 A B B 4B C B / 2 D 2B
 Question 18
The sensitiveness of a moving coil galvanometer can be increased by decreasing
 A The couple per unit twist of the suspension B The magnetic field C The area of the coil D The number of turns in the coil
 Question 19
Two parallel beams of electrons moving in the same direction produce a mutual force
 A Downwards perpendicular to plane of paper B Upwards perpendicular to plane of paper C Of repulsion in plane of paper D Of attraction in plane of paper
 Question 20
A uniform magnetic field acts at right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of  radius 2 cm. If the speed of the electrons is doubled, then the radius of the circular path will be
 A 4.0 cm B 2.0 cm C 0.5 cm D 1.0 cm
 Question 21
At a distance of 10 cm from a long straight wire carrying current, the magnetic field is 0.04 T. At the distance of 40 cm, the magnetic field will be
 A 0.16 T B 0.02 T C 0.01 T D 0.08 T
 Question 22
A charged particle is released from rest in a region of steady uniform electric and magnetic fields which are parallel to each other the particle will move in a
 A Straight line B Cycloid C Helix D Circle
There are 22 questions to complete.