Integrated Concepts A 5.00 g charged insulating ball hangs on a 30.0 cm long string in a uniform horizontal electric field as shown in Figure 18.56. Given the charge on the ball is 1.00 C , find the strength of the field.
Physics 2 for Engineering Week 9 Magnetic Field and Forces B – Magnetic field FB– Magnetic force Moving charge q ge1erates a magnetic field B, which exerts F on anBther moving charge q 2 FB= q v x B With charge q, velocity v, magnetic field generated B, and magnetic force exerted F B Unit of B is Tesla (T); 1 Tesla = 1 N/Am = 10 Gauss FBis perpendicular to both v and B Motion of charged particles in magnetic field 2 FBis a centripetal force; FB= q v B = m v R Radius of orbit R = m v / q B where v is perpendicular to B Time Period = 2 π R / v; Angular velocity ω = v / R = q B / m Dots = vector pointing out of plane; crosses = pointing into plane In presence of E and B field, F = F B F E Magnetic flux Φ = B x A if B is uniform/constant; Φ = ∫ B x dA if B is non-uniform/variable 2 Unit of magnetic flux is Weber, 1 Wb = 1 Tm ; scalar quantity Area vector is perpendicular to surface A; on closed surface A points out Magnetism A x B = ABsinθ A = A x + A jy+ A kz i x j = k j x i = -k j x k = i k x j = -i k x i = j i x k = -j Along a wire, F = I l x B = I l B sin θ Coil- loops are called turns Dipole magnetic moment μ = I A (where A is area of loop/turn); τ = μ x B = I B A sin θ
