#### Electrical engineering

• ( 1 ) A plane wave magnetic field is represented by Bx = cos(y - ct). The electric and magnetic fields will be zero in the direction

• 1) Ex = Ey = 0, By = Bz = 0.
• 2) Ey = Ez = 0, By = Bz = 0.
• 3) Ex = Ey = 0, Bx = By = 0.
• 4) None of these
• Discussion in forum
Answer : 1) Ex = Ey = 0, By = Bz = 0.
Solution : Wave propagating in (+ y) direction. H in (+ x) direction Then E will be in (+ z) direction. So, Ex = Ey = 0 and By = Bz = 0.

discussion

Answer : 1) Ex = Ey = 0, By = Bz = 0.

• ( 2 ) 1 Maxwell is the same as

• 1) 10-8 weber.
• 2) 108 weber.
• 3) 104 weber.
• 4) 10-4 weber.
• Discussion in forum
Solution : 1 Maxwell = 1 gauss x cm2 = 10-4 x (10-2)2 = 10-4 x 10-4 = 10-8 Weber.

discussion

• ( 3 ) A material with unequal anti-parallel atomic magnetic moments is

• 1) an anti-ferromagnet.
• 2) ferrimagnet
• 3) a ferrite.
• 4) non-magnetic
• Discussion in forum
Solution : An anti-ferromagnet is a material with unequal anti-parallel atomic magnetic moments.

discussion

• ( 4 ) The unit of electric field intensity is

• 1) N / C.
• 2) N / Ampere.
• 3) F / m.
• 4) F/ m2.
• Discussion in forum
Answer : 1) N / C.
Solution : Electric field intensity is the force experienced by a unit positive charge by another one charge. Hence, E = F / Q . Therefore, the unit of electric field is Newton per Coulomb.

discussion

Answer : 1) N / C.

• ( 5 ) XEROX machine is working on

• 1) magnetic effect.
• 2) electrostatic effect.
• 3) heating effect of cuurent.
• 4) peltier effect.
• Discussion in forum
Solution : The process is to spray the electric charge upon the semiconductor surface, and flash the image which would copy and the ink would permanently stick due to the hot pressure from the semiconductor surface.

discussion

• ( 6 ) Which of the following expression is correct for electric field strength?

• 1) E = πD2.
• 2) E = πD.
• 3) E = D2 / ε.
• 4) E = D / ε.
• Discussion in forum
Answer : 4) E = D / ε.
Solution : In a dielectric material, the presence of an electric field E causes the bound charges in the material to slightly separate. Hence, the electric displacement field D is defined as D = E x ε.

discussion

Answer : 4) E = D / ε.

• ( 7 ) Which of following is not a vector?

• 1) Linear momentum.
• 2) Angular momentum.
• 3) Electric potential.
• 4) Electric field.
• Discussion in forum
Solution : Angular momentum is not a vector.

discussion

• ( 8 ) Electric field intensity ( E ) at any point in an electric field is equal to

• 2) ( potential gradient )2.
• 3) ( potential gradient )1/2.
• 4) ( potential gradient )1/3.
• Discussion in forum
Solution : Electric field intensity ( E ) at any point in an electric field is equal to potential gradient

discussion

• ( 9 ) An electric field can deflect

• 1) gamma-rays.
• 2) x-rays.
• 3) alpha particles.
• 4) neutrons.
• Discussion in forum
Solution : X-rays are EM waves and they would not be deflected by electric field. Neutrons are not charged. Alpha particles are charged. Thus, alpha particles could be deflected by electric field, because only charged particles could interact with electric field.

discussion

• ( 10 ) Which of the following is unit of inductance ?

• 1) Webers/metre
• 2) Ampere turns
• 3) Henry
• 4) Ohm
• Discussion in forum