Reference no: EM13809000
1- according to Einstein theory, the energy of photon is
a- proportional to it wavelength
b- proportional to its frequency
c- constant, since the speed of light is a constant
d- quantized, since it always appears in bundles of size of 1.6x10^19C
e- proportional to the square of the frequency
2- source of sinusoidal electromagnetic waves radiates uniformly in all directions. At 8.70m from this source, the amplitude of the electric field is measured to be 2.15 N/C. What is the electric field amplitude at a distance of 24.8 cm from the source?
a- 96
b- 75.4
c- 36
d- 72
e- 69.5
3- A laser beam in air passes through a glass block and re-enters the air. How does the speed of the emerging beam compare to the speed in the glass ?
a- it is greater
b- it is the same
c- it is less
d- it can not be determined
e- it changes frequency
4- A square coil (length of side = 24cm) of wire consisting of two turns is placed in a uniform magnetic field that makes an angle of 60o with the plane of the coil. If the magnitude of this field increase by 6.0 mT every 10.0 ms, what is
the magnitude in mV of the emf induced in the coil?
a- 2.4
b- 48
c- 85
d- 60
e- 36
5- whenunpolarized light is passing through two polarizing filters in succession, its intensity is decreased by 87.5%. Determine the angle in degrees between the transmission axes of the two filters.
a- 15
b- 30
c- 60
d- 75
e- 20
6- what is the maximum radiation pressure in Pa exerted by sunlight in space(S= 1350 W/m^2) on a highly polished surface?
a- 1.4x10^-2
b- 0.12
c- 9.0x10^-6
d- 4.5x10^-5
e- 2.3x10^-6
7- the energy stored in a current-carrying inductor of inductance I
a- is equal to 2I^2
b- is directly proportional to I^2
c- is directly proportional to the square root of I
d- is directly proportional to I
e- is inversely proportional to I
8- A series RL circuits has a switch, a 12-V battery, a 100 resistors, and a 0.2 H inductor. The inductor is a coil open at both ends. An iron rod is inserted in the inductor and switch is closed. Compared to the same effect at the same time without the iron rod.
a- the potential difference across the resistor is greater
b- the potential difference across the inductor is decreased
c- the potential difference across the inductor increased
d- the power supplied by the battery is greater
e- the energy density of the magnetic field in the inductor is decreased
9- you have a 185 resistor, a 0.400 H inductor, and a 6.50 uF capacitor. Suppose you take the resistor and inductor and make a series circuits with a voltage source that has voltage amplitude 30.0 V and an angular frequency of 250 rads/s. what is the impedance of the circuits?
a- 110
b- 90
c- 360
d- 210
e- 550
10- In an L-R-C series circuit, R= 130, L= 0.480 H, C= 0.0250 uF.The source has a voltage amplitude V=150 v and a frequency equal to the resonance frequency of the circuit. What is the power factor?
a- 1
b- 0.8
c- 0.6
d- 0.4 e- 0.2