Physics - Study Mode
[#1006] In order to make an electromagnet you need a
Correct Answer
(D) All of the above
Explanation
Solution: In order to make an electromagnet you need a dry cell batteries, thin coated copper wire and iron nail.
[#1007] Which of the following is not a part of a CRT ?
Correct Answer
(D) Gas plasma
Explanation
Solution: The cathode ray tube (CRT) is a vacuum tube containing an electron gun (a source of electrons or electron emitter) and a fluorescent screen used to view images. Colour tubes use three different phosphors which emit red, green, and blue light respectively. They are packed together in stripes (as in aperture grille designs) or clusters called “triads” (as in shadow mask CRTs).
[#1008] Slip rings are usually made of
Correct Answer
(C) Phosphor Bronze
Explanation
Solution: Slip rings are usually made of Phosphor Bronze.
[#1009] The safest hammers are those with heads that are
Correct Answer
(B) Alloy and drop-forged steel
Explanation
Solution: The safest hammers are those with heads that are alloy and drop-forged steel.
[#1010] The function of ball bearings in a wheel is :
Correct Answer
(B) To convert kinetic friction into rolling friction
Explanation
Solution: A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. In general, it’s main function is to convert kinetic friction into rolling friction. It achieves this by using at least two races to contain the balls and transmit the loads through the balls.