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 applied across them so that the magnetic field at their centres is the same?
3
4
2
6
None of the above
A 10 eV electron is circulating in a plane at right angles to a uniform field of magnetic induction 10-4 Wb/m2 ( =1.0 gauss). The orbital radius of the electron is
12 cm
16 cm
11 cm
18 cm
The magnetic induction at a point P which is at the distance of 4 cm from a long current carrying wire is 10-3 T. The field of induction at a distance 12 cm from the current will be
3.33 × 10-4 T
1.11 × 10-4 T
3 × 10-3 T
9 × 10-3 T
Two equal electric currents are flowing perpendicular to each other as shown in the figure. AB and CD are perpendicular to each other and symmetrically placed with respect to the currents, where do we expect the resultant magnetic field to be zero?
On AB
On CD
On both AB and CD
On both OD and BO
The electron enters a region where magnetic field (B) and electric field (E) are mutually perpendicular, then
it will always move in the direction of B
it will always move in the direction of E
it always possess circular motion
it can go undeflected also
A charge moving with velocity v in X-direction is subjected to a field of magnetic induction in negative X – direction . As a result, the charge will
remain unaffected
start moving in a circular Y – Z plane
retard along X – axis
moving along a helical path around X – axis
A galvanometer of resistance 50 Ω is connected to a battery of 3 V along with a resistance of 2950 Ω 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
5050 Ω
5550 Ω
6050 Ω
4450 Ω
when a charged particle moving with velocity is subjected to a magnetic field of introduction , the force acting on it is non – zero. This implies that
Angle between is necessarily 90o
Angle between can have any value other than 90o
Angle between can have any value other than zero and 180o
Angle between is either zero or 180o
A straight wire of length 0.5 m and carrying a current of 1.2 A is placed in uniform magnetic field of induction 2 T. The magnetic field is perpendicular to the length of the wire. The force on the wire is
2. 4 N
1.2 N
3.0 N
2.0 N
