WorksheetsMoving charges and magnetism
Total questions: 15
Worksheet time: 1hrs 15mins
In a certain region of space, electric field
E and magnetic field
B are perpendicular to each other. An electron enters perpendicularly to both the fields and moves undeflected. The velocity of electron is
E/B
B/E
E x B
E.B
A deuteron of kinetic energy 50 keV is describing a circular orbits of radius 0.5 m in a plane perpendicular to the magnetic field B. The kinetic energy of the proton that describes a circular orbit of same radius and inside same B is
25 keV
50 keV
200 keV
100 keV
A rectangular coil ABCD is placed near a long straight current carrying straight wire as shown. What is the net force on the rectangular coil?
25 x 10-7 N towards the wire
25 x 10-7 N away from the wire
35 x 10-7 N, towards the wire
35 x 10-7 N, away from the wire
To convert a moving coil galvanometer into on ammeter of given range, we must connect:
A suitable low resistance in series
A suitable low resistance in parallel
A suitable high resistance in parallel
A suitable high resistance in series
Two wires of same length are shaped into a square and a circle if they carry same current, ratio of magnetic moment is :
2 : pi
pi: 2
pi: 4
4:pi
Current sensitivity of a galvanometer can be increased by decreasing :
Magnetic field B
number of turns N
torsional constant K
Area A
An electric current passes through a long straight copper wire. At a distance 5 cm from the straight wire, the magnetic field is B. The magnetic field at 20 cm from the straight wire would be
B/6
B/4
B/3
B/2
A wire in the form of a circular loop, of one turn carrying a current, produces magnetic induction B at the centre. If the same wire is looped into a coil of two turns and carries the same current, the new value of magnetic induction at the centre is
B
2B
4B
8B
Currents of 10 A and 2 A are flowing in opposite directions through two parallel wires A and B respectively. If the wire A is infinitely long and wire B is 2 m long, then force on wire B which is situated at 10 cm from A, is
8 x 10 ^ -5 N
6 x 10 ^-5 N
4 x 10 ^ -5 N
2 X 10 ^ -5 N
A 100 turns coil shown in the figure carries a current of 2 A in a magnetic field of .2Wbm2 The torque acting on the coil is
0.32 N-m tending to rotate the side AC into the page
0.32 N-m tending to rotate the side AC out of the page
0.64 N-m tending to rotate the side AC into the page
0.64 N-m tending to rotate the side AC out of the page
Current sensitivity of a galvanometer can be increased by decreasing (a) .
When a magnetic dipole of moment M rotates freely about its axis from unstable equilibrium
to stable equilibrium in a magnetic field B, the rotational kinetic energy gained by it is (a) .
An electron passes undeflected when passes through a region with electric and magnetic fields. When electric field is switched off its path will change to (a) .
Torque on a current carrying rectangular coil inside a galvanometer is maximum and constant irrespective of its orientation as it is suspended inside (a) magnetic field.
A linear conductor carrying current if placed parallel to the direction of magnetic field, then it experiences ---------------- force.
(a)
