A straight wire of mass 200 g and length 1.5 m carries a current of 2 A. It is suspended in mid-air by a uniform horizontal magnetic field B (shown in the figure). What is the magnitude of the magnetic field?
1. 0.65 T
2. 0.77 T
3. 0.44 T
4. 0.20 T
In a region of space, magnetic field is parallel to the positive y-axis and the charged particle is moving along the positive x-axis (as shown in the figure). The directions of Lorentz force for an electron (negative charge) and proton (positive charge) are respectively:
1. -z-axis, +z-axis
2. +z-axis, -z-axis
3. -z-axis, -z-axis
4. +z-axis, +z-axis
The radius of the path of an electron and frequency (mass and charge ) moving at a speed of 3 ×107 m/s in a magnetic field of 6 × 10–4 T perpendicular to it are respectively:
1. 24 cm, 4 MHz
2. 22 cm, 4 MHz
3. 28 cm, 2 MHz
4. 26 cm, 2 MHz
An electron is moving at a speed of 3 ×107 m/s in a magnetic field perpendicular to it. The energy of the electron in keV is: ( 1 eV = 1.6 × 10–19 J)
1. 2.5 keV
2. 3.5 keV
3. 20 keV
4. 3.0 keV
A cyclotron’s oscillator frequency is 10 MHz. The radius of its ‘dees’ is 60 cm, what should be the operating magnetic field for accelerating protons and the kinetic energy (in MeV) of the proton beam produced by the accelerator?
1. 0.66 T, 6 MeV
2. 0.33 T, 6 MeV
3. 0.66 T, 7 MeV
4. 0.33 T, 7 MeV
An element is placed at the origin and carries a large current of I =10 A (as shown in the figure). What is the magnetic field on the y-axis at a distance of 0.5 m? (∆x = 1 cm)
A straight wire carrying a current of 12 A is bent into a semi-circular arc of radius 2.0 cm as shown in the figure. Considering the magnetic field B at the centre of the arc, what will be the magnetic field due to the straight segments?
A straight wire carrying a current of 12 A is bent into a semi-circular arc of radius 2.0 cm as shown in the figure. Consider the magnetic field B at the centre of the arc. What is the magnetic field at centre due to the semi-circular loop?
Consider a tightly wound 100 turn coil of radius 10 cm, carrying a current of 1 A. What is the magnitude of the magnetic field at the centre of the coil?
The figure shows a long straight wire of a circular cross-section (radius a) carrying steady current I. The current I is uniformly distributed across this cross-section. If the magnetic field in the region (r < a) is and for (r > a) is , then is: