Q.1.
Which of the following represents Biot-Savart's law correctly? [ CBSE 1996]
-
24%
a)
-
19%
b)
-
46%
c)
-
12%
d)
Q.2.
An ideal transformer has primary power of 10kW. The secondary current when the transformer is on load is 25A. If the primary and secondary turns are in ratio is 8:1 then the potential difference applied in the primary coil is ...[ AFMC 1998]
-
20%
a)
-
28%
b)
-
41%
c)
-
11%
d)
Explanation
Q.3.
One tesla is equal to [ AFMC 1998]
-
37%
a) 104 gauss
-
19%
b) 10-8 gauss
-
24%
c)10-7 gauss
-
21%
d)10-4 gauss
Q.4.
Cyclotron is a device to .. [ AFMC 1998]
-
34%
a) accelerate electron
-
50%
b) accelerate proton
-
9%
c)measure voltage
-
7%
d)measure charge
Q.5.
If the incuced emf's in the primary and secondary coils of inductance is 2mV and 5.12 mV when the rate of change of current through either of these is 20 ampere per second. If the coefficient of coupling is one, the mutual inductance is ... [ AFMC 1998]
-
16%
a) 3.56 ×10-4 henry
-
28%
b) 1.56 × 10-4 henry
-
42%
c) 1.6 × 10-4 henry
-
14%
d) 2.56 × 10-4 henry
Explanation
Q.6.
A current carrying wire in the neighborhood produces ...[AFMC 1999]
-
59%
a)electric and magnetic fields
-
29%
b) magnetic field only
-
3%
c)no field
-
8%
d)electric field
Q.7.
Two parallel wire in free space are 10 cm apart and each carries a current of 10A in the same direction. The force exerted by one wire on other per metre of length of the wire is..[ AFMC 1999]
-
22%
a) 2×10-6N
-
41%
b) 2×10-4N
-
30%
c)2×10-3N
-
8%
d)2×10-2N
Explanation
Q.8.
A long hollow copper pipe carries a current, then magnetic field produced is ..... [ AFMC 1999]
-
43%
a) both inside and outside the pipe
-
18%
b) neither inside nor outside the pipe
-
32%
c)outside the pipe only
-
7%
d)inside the pipe only
Explanation
Q.9.
A cyclotron is operating at frequency of 12×106Hz. Mass of deuteron is 3.3× 10-27Kg and charge on deuteron is 1.6×10-19 coulombTo accelerate deuterons the magnetic induction of the necessary magnetic field is ..[ AFMC 2000]
-
22%
a) 0.016 tesla
-
30%
b) 0.16 tesla
-
30%
c) 16 tesla
-
19%
d) 1.6tesla
Explanation
Q.10.
A galvanometer of 100Ω resistance gives full scale deflection with 0.01A current. How much resistance should be connected convert it into an ammeter of range 10A? [ AFMC 2002]
-
45%
a)0.1 Ω in parallel
-
24%
b) 0.1Ω in series
-
21%
c)0.2Ω in parallel
-
10%
d)0.2 Ω in series
Q.11.
The magnetic field Bo due to current carrying circular loop of radius 12cm at its center is 0.5 ×10-4T. The magnetic field due to this loop at a point on the axis at a distance of 5cm from the center is .. [ AFMC 2002]
-
30%
a) 3.9×10-5 T
-
30%
b) 9.3×10-5 T
-
20%
c)6.3×10-15 T
-
20%
d) 3.6×10-5 T
Explanation
Q.12.
To convert a galvanometer into voltmeter we must connect a ...[ AFMC 2002]
-
50%
a) high resistance in series
-
23%
b) low resistance in parallel
-
27%
c)high resistance in parallel
-
0%
d)low resistance in series
Q.13.
Two wires carry current in different direction they will ...[ AFMC 2003]
-
46%
a) attract each other
-
46%
b) repel each other
-
0%
c) create gravitational field
-
8%
d) any of the above
Q.14.
To convert a galvanometer into an ammeter, one needs to connect a [ CBSE-PMT 1992]
-
64%
a)low resistance in parallel
-
7%
b) high resistance in parallel
-
14%
c)low resistance in series
-
14%
d)high resistance in series
Q.15.
Energy in a current carrying coil is stored in the form of ... [ CBSE-PMT 1989]
-
29%
a) electric field
-
39%
b) magnetic field
-
18%
c)dielectric strength
-
14%
d)heat
Q.16.
A coil carrying electric current is placed in uniform magnetic field, then... [ CBSE-PMT 1993]
-
29%
a)torque is formed
-
14%
b) e.m.f. is induced
-
50%
c)both (a) and (b) are correct
-
7%
d)none of the above
Q.17.
A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will.. [ CBSE-PMT 1997]
-
21%
a) continue to move due east
-
54%
b) move in a circular orbit with its speed unchanged
-
21%
c) move in a circular orbit with its speed increases
-
4%
d) get deflected vertically upwards
Q.18.
A straight wire of diameter 0.5mm carrying a current of 1A is replaced by another wire of 1mm diameter carrying same current. The strength of magnetic field far away is ... [ CBSE-PMT 1999]
-
24%
a)twice the earlier value
-
36%
b) same as earlier value
-
40%
c)one-half of the earlier value
-
0%
d)one-quarter of the earlier value
Q.19.
If a long hollow copper pipe carries a current then magnetic field is produced.. [ CBSE-PMT 1999]
-
16%
a) inside the pipe only
-
68%
b) outside the pipe only
-
16%
c)both inside and outside the pipe
-
0%
d)no where
Q.20.
A galvanometer can be converted into a voltmeter by connecting .. [ CBSE-PMT 2002]
-
29%
a)A high resistance in parallel
-
24%
b) A low resistance in series
-
38%
c)A high resistance in series
-
10%
d)A low resistance in parallel
Q.21.
A galvanometer acting like a voltmeter will have .. [ CBSE-PMT 2004]
-
20%
a) a low resistance in series with its coil
-
10%
b) a high resistance in parallel with its coil
-
60%
c) high resistance in series with its coil
-
10%
d) low resistance in parallel with its coil
Q.22.
A 10 eV electron is circulating in a plane at right angle to uniform field of magnetic induction 10-4 Wb/mThe orbital radius of the electron is .. [ CBSE-PMT 1996]
-
15%
a)12 cm
-
40%
b) 16 cm
-
35%
c)11 cm
-
10%
d)18 cm
Explanation
Q.23.
When a charged particle moving with velocity v is subjected to a magnetic field of induction B, the force on it is zero. This implies that... [ CBSE-=PMT 2006]
-
17%
a) angle between v and B can have any value other than 90°
-
38%
b) angle between v and B can have any value other than zero and 180°
-
29%
c)angle between v and B is either zero or 180°
-
17%
d)angle between v and B is necessarily 90°
Q.24.
A particle of mass m, charge Q and kinetic energy T enters a transverse uniform magnetic field of induction B. After 3 seconds, the kinetic energy of the particle will be... [CBSE-PMT 2008]
-
30%
a)3T
-
25%
b)2T
-
40%
c)T
-
5%
d)4T
Q.25.
An electron moves in circular orbit with uniform speed v. It produces a magnetic field B at the centre of the circle. the radius of the circle is proportional to ... [ CBSE-PMT 2005]
-
13%
a)
-
35%
b)
-
39%
c)
-
13%
d)
Explanation
Q.26.
A beam of electron passes un deflected through mutually perpendicular electric field and magnetic field. If the electric field is switched off, and the same magnetic field is maintained, the electrons move ... [ CBSE-PMT 2007]
-
40%
a)in a circular orbit
-
15%
b) along a parabolic path
-
40%
c)along a straight line
-
5%
d)in an elliptical orbit
Q.27.
A beam of electrons is moving with constant velocity in a region having simultaneous perpendicular electric and magnetic fields of strength 20V/m and 0.5T respectively at right angles to the direction of motion of the electrons. Then the velocity of electrons must be .. [ CBSE-PMT 1996]
-
6%
a) 8 m/s
-
18%
b) 20m/s
-
59%
c)40 m/s
-
18%
d)(1/40) m/s
Q.28.
A particle having charge q moves with velocity v through a region in which both an electric field E and magnetic field B are present. The force on the particle is ... [ CBSE-PMT 2002]
-
48%
a) qE + q( v × B )
-
10%
b) qE ⋅ q( B × v )
-
14%
c)qv + q( E × B )
-
29%
d)qE × q( B × v )
Q.29.
When a proton is accelerated through 1V then its kinetic energy will be... [ CBSE-PMT 1999]
-
16%
a) 1840 eV
-
16%
b) 13.6eV
-
58%
c) 1 eV
-
11%
d) 0.54eV
Q.30.
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 F, the net force on the remaining three arms of the loop is .. [ CBSE-PMT 2010]
-
24%
a)3F
-
29%
b) -F
-
38%
c)-3F
-
10%
d)F