Electricity (Part-2)

51. Which of the following statements is correct? [S.S.C. Online Graduation Level (T-1) 18.08.2021 (Shift-I)]

(a) Earth's magnetic poles coincide with the geographic poles.
(b) The net magnetic flux through any closed surface is zero.
(c) Two magnetic field lines may intersect.
(d) Magnetic flux is a vector quantity.

Correct Answer: (b) The net magnetic flux through any closed surface is zero.

Solution:The net magnetic flux through a closed surface is zero because the magnetic force lines in a closed surface are in opposite directions, as many lines enter such a surface as they exit.

52. Which of the following is one of the metals used in LED semiconductor technology? [S.S.C. Online Graduation Level (T-1) 16.08.2021 (Shift-II)]

(a) Copper
(b) Iron
(c) Zinc
(d) Gallium

Correct Answer: (d) Gallium

Solution:One of the metals used in LED (Light Emitting Diode) semiconductor technology is Gallium (Ga).

Gallium is a primary element used in the manufacturing of almost all semiconductor LED devices. It is often combined with other elements like Arsenic (As) and Phosphorus (P) to create semiconductor materials such as Gallium Arsenide (GaAs), Gallium Phosphide (GaP), and Gallium Arsenide Phosphide (GaAsP), which emit light of different colors.

53. Which of the following statements is not true regarding electromagnets? [S.S.C. Online MTS (T-1) 6.10.2017 (Shift-I)]

(a) They do not lose magnetism when an electric current is switched off.
(b) They can be made very strong to lift heavy objects
(c) They are used to separate magnetic material from junk
(d) They attract pieces of iron.

Correct Answer: (a) They do not lose magnetism when an electric current is switched off.

Solution:Electromagnets are made by placing an iron core in a coil made of insulated copper wire. It behaves like a magnet when current is passed through the coil, but its magnetism ends when the current is stopped.

54. A device that can be used to test whether an object is carrying a charge or not is known as: [S.S.C. JE Mechanical Exam 27.10.2920 (Shift-I)]

(a) Gyroscope
(b) Electroscope
(c) Microscope
(d) Kalidoscope

Correct Answer: (b) Electroscope

Solution:An electroscope is an instrument with the help of which the presence and absence of charge on any object are detected. In other words, an electroscope is used in the detection and measurement of electric charge.

Electricity (Part-2)

51. Which of the following statements is correct? [S.S.C. Online Graduation Level (T-1) 18.08.2021 (Shift-I)]

52. Which of the following is one of the metals used in LED semiconductor technology? [S.S.C. Online Graduation Level (T-1) 16.08.2021 (Shift-II)]

53. Which of the following statements is not true regarding electromagnets? [S.S.C. Online MTS (T-1) 6.10.2017 (Shift-I)]

54. A device that can be used to test whether an object is carrying a charge or not is known as: [S.S.C. JE Mechanical Exam 27.10.2920 (Shift-I)]

Related Posts