Gravity pushes against all objects, trying to crush it. What pushes against gravity in: a main sequence star, a white dwarf, a neutron star, and a black hole?

Question 7 [2 marks] in the circuit below, the electromotive force generated by the battery is e = 6.0 v, and the resistances are r1 = r4 = 1.0 q, r2 = r3 =2.0 q. r. the power delivered by the battery to the circuit is closest to a. 6 w в. 12 w с. 15 w d. 18 w e. 20 w final exam autumn 2014 page 5 of 9 68037 physical modelling faculty of science [2 mark] question 8 with reference to question 7, the current through resistor r2 is closest to a. 1 a в. 2 а c. 3 a d. 4 a e. 6 a

Which of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?