Question

A uniform magnetic field points directly into your paper (make a sketch). A 7 turn coil of wire with a radius of 14.2 cm lies in the plane of the paper. Over a period of 0.00035 seconds, the field is increased from 0.300 T to 1.10 T. How much emf is induced in the coil while B is changing? A-0.12 volts B- 0.91 volts C-28 volts D- 16,000 volts E- 250 volts Which way is the induced emf (or induced current) in the question above? A- Right B-out of the paper C-left D-clockwise E- Into the paper Recently a star with several possibly earth-like planets was discovered. It is 3x10^18 m from earth. How long does it take light from that start to reach earth? A-1.5x10^4 s B-3.2x10^7 C-2.4x10-9 s D- 3x10^8 s E- 1x10^10 A small object is placed 25.0 cm from a converging lens of focal length 40.0 cm. The object is to the left of the lens. Where is the image? A- 17cm to the right of the lens B-25cm to the left of the lens C- 17 cm to the left of the lens D-25 cm to the right of the lens E-67cm to the right of the lens F-67 cm to the left of the lens A small object is placed 25 cm to the left of a converging lens of focal length 40 cm (same as question 11). Which statement is true about the image? A- it is real, inverted and large than the object B- it is real, upright and larger than the object C-it is real, inverted and smaller than the object D-it is virtual inverted and larger than the object E- it is virtual upright and larger than the object F-It is virtual inverted smaller than the object A small object is placed 50 cm from a convex mirror producing an upright image which is 0.60 times as high as the object. What is the focal length of the mirror? A-(-19cm) B-30cm C-(-75) D- (75) E- 19 F-(-30)

Answer 1

The answers given for first question is incorrect

The solution is given below.

1. 01142 m 77 radius No 14.2 cm - ricroca & Tor *(0.142)"= 01063344 m Magnetic field changes from 0.300T to 1.1oT in seconds, 0.00035 induced enf no of thronsy Change in flux time 0.300 ) 0. 063347 (1.10-01 0.00035 Answer: - 1013.55 volts 1013.55 volts, 2 indreed rent will be direction of such that it opposes the chang in this emp is to the Right Answer: Right. 3 speed of light 8 mis I 3x10 time taken by Light to reach eartha 3x1018 3x108 Answer :I. 1x1018 - lxiolos S lens formula 1 di do f + 20 di image distance to focal length = 40 cm don object distance - 250m 1 25 40 d -0.0IS idi. - 66.67 cm - 67 en negative sign indicates image is in the reft of the runs. Answer: F. 67 cm of the left of the leas,

Question 5 : &. It is virtual upright and larger than the object, F f image object magnifications a 60 image distance - 0.60x object distance 0.60 x 50 - 30 un from mirror formula el do to di f fa focal length dit image distance do sobject distance - - 50 con - 30 ur ol 7: 고 50 30 -0.01333 of or fa 75 cm Answer: 75

Thank you.