28/03/2020 Magnetism and Electromagnetic Effects(Senior Class Physics Study by Topics) 28/03/2020 0Comments by Gate Academy Welcome to your Magnetism and Electromagnetic Effects(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. Which of the following is not a unit of flux? Maxwell All of the above Tesla Weber 2. Indicate which of the following material does not retain magnetism permanently.(A) Soft iron Hardened steel Soft iron Stainless steel None of the above 3. A vertical wire carries an electric current into the page. What is the direction of the magnetic field at point P located to the south from the wire? West. South North. East 4. An advantage of a magnetic disk, compared with magnetic tape, for data storage and retrieval is that A disk lasts longer. Disks are less susceptible to magnetic fields. Disks look better. Data can be stored and retrieved more quickly with disks than with tapes. 5. How can you make a magnet temporarily lose its magnetism? By hitting it very hard By heating it Both a & c By blowing on it 6. An advantage of an electromagnet over a permanent magnet is the fact that Permanent magnets must always be cylindrical, but electromagnets can have any shape An electromagnet can be switched on and off. An electromagnet does not have specific polarity. An electromagnet requires no power source. 7. Ampere-turn is the unit of magneto-motive force (mmf). True False 8. A magnetic hard disk is usually part of A dc motor. A tape recorder. A computer. An electromagnet 9. Earth’s magnetic field and a bar magnet both attract particles to the same locations. Where are they? The North and South poles First to the middle, then to the ends All around the outside The middle 10. A straight long wire carries an electric current to the top of the page. The current is placed in a uniform magnetic field directed out the page. What is the direction of the magnetic force on the current? To the bottom of the page To the top of the page Right Left. 11. The presence of a magnetic field can always be attributed to Motion of electric charge carriers. Diamagnetic materials The north geomagnetic pole Ferromagnetic materials. 12. A bar magnet is divided in two pieces. Which of the followingstatements is true? The electric field is created Two new bar magnets are created. The magnetic field of each separated piece becomes stronger. The bar magnet is demagnetized. 13. The smallest particle of an element is known as an: Neutron Electron Proton Atom 14. A certain amount of current flows through a ring-shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil? Increases First increases and then decreases depending on the depth of iron insertion Remains same Decreases 15. Any magnet has two ends, each one called a: None of the above Magnitized material Magnetic field Magnetic pole 16. Which of the following can occur during a geomagnetic storm? Charged particles stream out from the sun. More than one of the above can occur Electrical power transmission is disrupted. The earth’s magnetic field is affected. 17. A current-carrying wire is placed perpendicular to the page. Determine the direction of the electric current from the direction of the magnetic field Out of the page. Counter-clockwise. Into the page. Clockwise. 18. A tiny, negatively charged particle that usually exists in the outer region of an atom is called a: Proton Electron Neutron Nucleus 19. A straight long wire carries an electric current out the page. The current is placed in a uniform magnetic field directed into the page. What is the direction of the magnetic force on the current? To the bottom of the page There is no magnetic force on the current To the top of the page. Left. 20. A vertical wire carries an electric current out of the page. What is the direction of the magnetic field at point P located to the west from the wire? East. North. South. West. 21. If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity Equal to that of disc and in the same direction Less than that of disc and in the same direction Equal to that of disc and in the opposite direction Less than that of disc but in opposite direction 22. An object is not magnetized if: The groupings of atoms are scattered The groupings of atoms are lined up The groupings of atoms are in the same direction 23. If a wire coil has 100 turns and carries 1.30 A of current, what is the magnetomotive force? 164 Gb 76.9 Gb 61.0 Gb 130 Gb 24. If a wire coil has 10 turns and carries 500 mA of current, what is the magnetomotive force? 0.02 At 5.0 At 50 At 5000 At 25. A ferromagnetic material is: A material that shows strong magnetic effects A material that shows no magnetic effects A material that shows weak magnetic effects 1 out of 25 Time is Up! Time's up