Electromagnetics Field (3140912) MCQs

MCQs of Magnetic forces, materials and inductance

Showing 151 to 160 out of 171 Questions
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151.
Two differential current elements, I1dL1 = 3×10–6(āy) A-m at P1(1, 0, 0) and I2dL2 = 3×10–6(−0.5āx+0.4āy+0.3āz) A-m at P2(2, 2, 2) are located in free space. What will be the differential force on I2dL2 by I1dL1?
(a) (−1.33āx+0.33āy−2.67āz)×10–20 N
(b) (4.67āx+0.67āz)×10–20 N
(c) (−1.33āx+0.33āy−2.67āz) N
(d) (4.67āx+0.67āz) N
Answer:

Option (a)

152.
Two differential current elements, I1dL1 = 3×10–6(āy) A-m at P1(1, 0, 0) and I2dL2 = 3×10–6(−0.5āx+0.4āy+0.3āz) A-m at P2(2, 2, 2) are located in free space. What will be the differential force on I1dL1 by I2dL2?
(a) (−1.33āx+0.33āy−2.67āz)×10–20 N
(b) (4.67āx+0.67āz)×10–20 N
(c) (−1.33āx+0.33āy−2.67āz) N
(d) (4.67āx+0.67āz) N
Answer:

Option (b)

153.
What will be the inductance of a toroid formed by surfaces r = 3 cm , r = 5 cm, z = 0 cm and z = 1.5 cm, wrapped with 5000 turns and filled with magnetic material with relative permeability, μr = 6?
(a) 229 μH
(b) 0.229 H
(c) 0.229 μH
(d) 229 H
Answer:

Option (b)

154.
A solenoid has an inductance of 20 mH. If the length of solenoid is increased by two times and radius is decreased to half of its original value. What will be the new inductance of solenoid?
(a) 2.5 H
(b) 25 mH
(c) 2.5 mH
(d) 0.25 H
Answer:

Option (c)

155.
An electron with velocity, v = (3āx+12āy−4āz) ×105 m/s experiences no net forces at a point in a magnetic field, B = 1āx+2āy+3āz mWb/m2. The electric field E at that point is
(a) −4.4āx+1.3āy+0.6āz kV/m
(b) 4.4āx−1.3āy−0.6āz kV/m
(c) −4.4āx+1.3āy+0.6āz V/m
(d) 4.4āx−1.3āy−0.6āz V/m
Answer:

Option (a)

156.
A point charge of 2×10–16 C and 5×10–26 kg moving in the combined fields of B = –3āx+2āy–1āz mT and E = 100āx–200āy+300āz V/m. If the charge velocity at t = 0 is v(0) = (2āx–3āy–4āz)×105 m/s, the acceleration of charge at t = 0 is
(a) 600×109(3āx+2āy–3āz) m/s2
(b) 400×109(6āx+6āy–3āz) m/s2
(c) 400×109(6āx–6āy+3āz) m/s2
(d) 800×109(6āx+6āy–āz) m/s2
Answer:

Option (d)

157.
A rectangular loop of wire in free space joins points A(1, 0, 1) to B(3, 0, 1) to C(3, 0, 4) to D(1, 0, 4) to A. The wire carries a current of 6 mA flowing in the (āz)direction from B to C. A filamentary current of 15 A flows along the entire z, axis in the (āz) directions. The force on side BC is
(a) –18āx nN
(b) 18āx nN
(c) 3.6āx nN
(d) –3.6āx nN
Answer:

Option (a)

158.
A rectangular loop of wire in free space joins points A(1, 0, 1) to B(3, 0, 1) to C(3, 0, 4) to D(1, 0, 4) to A. The wire carries a current of 6 mA flowing in the (āz)direction from B to C. A filamentary current of 15 A flows along the entire z, axis in the (āz) directions. The force on side AB is
(a) 23.4āz nN
(b) 16.4āz nN
(c) 19.8āz nN
(d) 26.3āz nN
Answer:

Option (c)

159.
Two infinitely long parallel filaments each carry 100 A in the āz direction. If the filaments lie in the plane y = 0 at x = 0 and x = 5 mm the force on the filament passing through the origin is
(a) 0.4āx N/m
(b) –0.4āx N/m
(c) 4āx N/m
(d) –4āx N/m
Answer:

Option (a)

160.
In a certain material for which, μr = 6.5 and H = 10āx+25āy−40āz A/m. The magnetic susceptibility χm of the material is
(a) 5.5
(b) 6.5
(c) 7.5
(d) None of above
Answer:

Option (a)

Showing 151 to 160 out of 171 Questions
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