2010
NEET
MCQ
AIPMT 2010 Mains
A particle having a mass of 10$-$2 kg carries a charge of 5 $ \times $ 10$-$8 C. The particle is given an initial horizontal velocity of 105 m s$-$1 in the presence of electric field $\overrightarrow E $ and magnetic field $\overrightarrow B $. To keep the particle moving in a horizontal direction, it is necessary that
(1) $\overrightarrow B $ should be perpendicular to the direction of velocity and $\overrightarrow E $ should be along the direction of velocity
(2) Both $\overrightarrow B $ and $\overrightarrow E $ should be along the direction of velocity
(3) Both $\overrightarrow B $ and $\overrightarrow E $ are mutually perpendicular and perpendicular to the direction of velocity.
(4) $\overrightarrow B $ should be along the direction of velocity and $\overrightarrow E $ should be perpendicular to the direction of velocity
Which one of the following pairs of statements is possible ?
(1) $\overrightarrow B $ should be perpendicular to the direction of velocity and $\overrightarrow E $ should be along the direction of velocity
(2) Both $\overrightarrow B $ and $\overrightarrow E $ should be along the direction of velocity
(3) Both $\overrightarrow B $ and $\overrightarrow E $ are mutually perpendicular and perpendicular to the direction of velocity.
(4) $\overrightarrow B $ should be along the direction of velocity and $\overrightarrow E $ should be perpendicular to the direction of velocity
Which one of the following pairs of statements is possible ?
A.
(1) and (3)
B.
(3) and (4)
C.
(2) and (3)
D.
(2) and (4)
2010
NEET
MCQ
AIPMT 2010 Mains
A current loop consists of two identical semicircular parts each of radius R, one lying in the x-y plane and the other in x-z plane. If the current in the loop is $i$. The resultant magnetic field due to the two semicircular parts at their common centre is
A.
${{{\mu _0}i} \over {2\sqrt 2 R}}$
B.
${{{\mu _0}i} \over {2R}}$
C.
${{{\mu _0}i} \over {4R}}$
D.
${{{\mu _0}i} \over {\sqrt 2 R}}$
2010
NEET
MCQ
AIPMT 2010 Prelims
A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be
A.
900 $\Omega $
B.
1800 $\Omega $
C.
500 $\Omega $
D.
1000 $\Omega $
2010
NEET
MCQ
AIPMT 2010 Prelims
A square current carrying loop is suspended in a uniform magnetic field acting in the plane of the loop. If the force on one arm of the loop is the net force on the remaining three arms of the loop is
A.
$3\overrightarrow F $
B.
$-$ $\overrightarrow F $
C.
$-$ $3\overrightarrow F $
D.
$\overrightarrow F $
2010
NEET
MCQ
AIPMT 2010 Prelims
Charge q is uniformly spread on a thin ring of radius R. The ring rotates about its axis with a uniform frequency $f$ Hz. The magnitude of magnetic induction at the center of the ring is
A.
${{{\mu _0}qf} \over {2\pi R}}$
B.
${{{\mu _0}qf} \over {2R}}$
C.
${{{\mu _0}q} \over {2fR}}$
D.
${{{\mu _0}q} \over {2\pi fR}}$
2010
NEET
MCQ
AIPMT 2010 Prelims
A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be
A.
900 $\Omega $
B.
1800 $\Omega $
C.
500 $\Omega $
D.
1000 $\Omega $
2009
NEET
MCQ
AIPMT 2009
The magnetic force acting on a charged particle of charge $-$2 $\mu $C in a magnetic frield of 2 T acting in y direction, when the particle velocity is $\left( {2\widehat i + 3\widehat j} \right) \times {10^6}\,m{s^{ - 1}}$
A.
4 N in z direction
B.
8 N in y direction
C.
8 N in z direction
D.
8 N in $-$ z direction
2009
NEET
MCQ
AIPMT 2009
A galvanometer havings a coil resistance of 60 $\Omega $ shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents upto 5.0 amp by
A.
putting in series a resistance of 15 $\Omega $
B.
putting in series a resistance of 240 $\Omega $
C.
putting in parallel a resistance of 15 $\Omega $
D.
putting in parallel a resistance of 240 $\Omega $
2009
NEET
MCQ
AIPMT 2009
Under the influence of a uniform magnetic field, a charged particle moves with constant speed v in a circle of radius R. The time period of rotation of the particle
A.
depends on R and not on v
B.
is independent of both v and R
C.
depends on both v and R
D.
depends on v and not on R
2008
NEET
MCQ
AIPMT 2008
A particle of mass m, charge Q and kinetic energy T enters a transverse uniform magnetic field of induction $\overrightarrow B $. After 3 seconds the kinetic energy of the particle will be
A.
T
B.
4 T
C.
3 T
D.
2 T
2008
NEET
MCQ
AIPMT 2008
A closed loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR and RQ are F1, F2 and F3 respectively and are in the plane of the paper and along the directions shown, the force on the segment QP is
A.
$\sqrt {{{\left( {{F_3} - {F_1}} \right)}^2} - F_2^2} $
B.
${F_3} - {F_1} + {F_2}$
C.
${F_3} - {F_1} - {F_2}$
D.
$\sqrt {{{\left( {{F_3} - {F_1}} \right)}^2} + F_2^2} $
2008
NEET
MCQ
AIPMT 2008
A galvanometer of resistance 50 $\Omega $ is connected to a battery of 3 V along with a resistance of 2950 $\Omega $ in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
A.
$6050$ $\Omega $
B.
$4450\,\Omega $
C.
$5050\,\Omega $
D.
$5550\,\Omega $
2007
NEET
MCQ
AIPMT 2007
Under the influence of a uniform magnetic field, a charged particle moves with constant speed v in a circle of radius R. The time period of rotation of the particle
A.
depends on R and not on v
B.
is independent of both v and R
C.
depends on both v and R
D.
depends on v and not on R
2007
NEET
MCQ
AIPMT 2007
The resistance of an ammeter is 13 $\Omega $ and its scale is graduated for a current upto 100 amps. After an additional shunt has been connected to this ammeter it becomes possible to measure currents upto 750 amperes by this meter. The value of shunt-resistance is
A.
2 $\Omega $
B.
0.2 $\Omega $
C.
2 k$\Omega $
D.
20 $\Omega $
2006
NEET
MCQ
AIPMT 2006
Two circular coils 1 and 2 are made from the same wire but the radius of the 1st coil is twice that of the 2nd coil. What is the ratio of potential difference in volts should be applied across them so that the magnetic field at their centres is the same?
A.
2
B.
3
C.
4
D.
6
2006
NEET
MCQ
AIPMT 2006
When a charged particle moving with velocity $\overrightarrow v $ is subjected to a magnetic field of induction $\overrightarrow B $, the force on it is non-zero. This implies that
A.
angle between is either zero or 180o
B.
angle between is necessarily 90o
C.
angle between can have any value other than 90o
D.
angle between can have any value other than zero and 180o.
2005
NEET
MCQ
AIPMT 2005
A very long straight wire carries a current $I$. At the instant when a charge +Q at point P has velocity $\overrightarrow v $, as shown, the force on the charge is
A.
along Oy
B.
opposite to Oy
C.
along Ox
D.
opposite to Ox
2005
NEET
MCQ
AIPMT 2005
An electron moves in a circular orbit with a uniform speed v. It producess a magnetic field B at the centre of the circle. The radius of the circle is proportional to
A.
$\sqrt {B/v} $
B.
$B/v$
C.
$\sqrt {v/B} $
D.
$v/B$
2004
NEET
MCQ
AIPMT 2004
To convert a galvanometer into a voltmeter one should connect a
A.
high resistance in series with galvanometer
B.
low resistance in series with galvanometer
C.
high resistance in parallel wilh galvanometer
D.
low resistance in parallel with galvanometer.
2004
NEET
MCQ
AIPMT 2004
A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 $ \times $ 10$-$4 ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of
A.
$2500\,\Omega $ as a shunt
B.
2450 $\Omega $ as a shunt
C.
2550 $\Omega $ in series
D.
2450 $\Omega $ in series
2003
NEET
MCQ
AIPMT 2003
A long solenoid carrying a current producess a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is
A.
B/2
B.
B
C.
2B
D.
4B
2003
NEET
MCQ
AIPMT 2003
A charged particle moves through a magnetic field in a firection perpendicular to it. Then the
A.
speed of the particle remains unchanged
B.
direction of the particle remains unchanged
C.
acceleration remains unchanged
D.
velocity remains unchanged
2002
NEET
MCQ
AIPMT 2002
To convert a galvanometer into a voltmeter one should connect a
A.
high resistance in series with galvanometer
B.
low resistance in series with galvanometer
C.
high resistance in parallel with galvanometer
D.
low resistance in parallel with galvanometer.
2002
NEET
MCQ
AIPMT 2002
The magnetic field of given length of wire for single turn coil at its centre is B then its value for two turns coil for the same wire is
A.
B/4
B.
B/2
C.
4B
D.
2B
2002
NEET
MCQ
AIPMT 2002
A charge q moves in a region where electric field and magnetic field both exist, then force on it is
A.
$q\left( {\overrightarrow v \times \overrightarrow B } \right)$
B.
$q\overrightarrow E + q\left( {\overrightarrow v \times \overrightarrow B } \right)$
C.
$q\overrightarrow E + \overrightarrow q \left( {\overrightarrow B \times \overrightarrow v } \right)$
D.
$q\overrightarrow B + \overrightarrow q \left( {\overrightarrow E \times \overrightarrow v } \right)$
2001
NEET
MCQ
AIPMT 2001
If number of turns, area and current through a coil is given by n, A and $i$ respectively then its magnetic moment will be
A.
$niA$
B.
${n^2}iA$
C.
$ni{A^2}$
D.
${{ni} \over {\sqrt A }}$
2001
NEET
MCQ
AIPMT 2001
An electron having mass m and kinetic energy E anter in uniform magnetic field B perpendiculaly, then its frequency will be
A.
${{eE} \over {qvB}}$
B.
${{2\pi m} \over {eB}}$
C.
${{eB} \over {2\pi m}}$
D.
${{2m} \over {eBE}}$
2000
NEET
MCQ
AIPMT 2000
The magnetic field at centre, P will be
A.
${{{\mu _0}} \over {4\pi }}$
B.
${{{\mu _0}} \over {\pi }}$
C.
${{{\mu _0}} \over {2\pi }}$
D.
$4{\mu _0}\pi $