Question

For which of the following d will current flow through the light bulb? (all coils are complete closed circuit) a. 1 b. 2 c. 3 d. 4 e. 1 and 2 A bar magnet is falling through a loop of wire with constant velocity. The south pole enters first. As the south pole of the magnet approaches the wire, the induced current (as viewed from above): a. is clockwise. b. counterclockwise. c. is zero. d. is along the length of the magnet 3. The speed of ultraviolet radiation in vacuum compared with the speed of visible light in vacuum is a. very much greater. b. a little greater. c. the same d. a little less. e, very much less. The wavelength of 200-MHz television signal is approximately: a. 1.0 m b. 1.5 m c. 2.0 m d. 2.0 cm e. 50 cm

Answer 1

1 ans

the current passing 1 and 2

becasue the magnet is placed closed the loop the current is passing but in the loop 3 and 4 the current is does not passed because there is no change of flux linked with the coil

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2 ans

basing on the faradays law the south pole entre to first in the loop the current is induced clockwise

the correct option B

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3 ans

speed of UV light in vacum=2.9934*10^8 m/s

speed of visble light in vaccum =2.998*10^8 m/s

basing on this correct option is D

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4 ans

frequency f=200 Mhz=200*10^6 Hz

now we find the wavelength

wavelength=3*10^8/2*10^8=1.5 m

the correct option is B