Physics Vectors Level: University
Three vectors A B and C together to yield zero: A + B + C = 0. The vectors A and C point in opposite directions and their magnitudes are related by the expression: A = 2c. Which one of the following conclusions is current?a. A and B have equal magnitudes and point in opposite directions
b. B and C have equal magnitudes and point in same direction.
c. B and C have equal magnitudes and point in opposite directions.
d. A and B point in the same direction but C has twice the magnitude of B.
e. B and C point in the same direction but C has twice the magnitude of B .
Physics Units Level: University
DimensionA curtain physical quantity R is calculated using the formula:4a2 (b - c) where a b and c are distances.What is the SI unit for R?
(a) cm
(b) cm2
(c) m
(d) m2
(e) m3
Physics Work,Power & Energy Level: University
Conservation of momentumAn object initially at rest breaks into two pieces as the result of an explosion. One piece (m^2) has four times the kinetic energy of the other piece (m1). What is the ratio of the masses of the two pieces?
m1/m2=
Which piece has the larger mass?
The masses must be equal.
The piece with the larger kinetic energy.
The piece with the smaller kinetic energy.
Physics Work,Power & Energy Level: University
Conservation of momentumTwo ice skaters stand at rest in the center of an ice rink. When they push off against one another the 45 kg skater acquires a speed of 0.72m/s. If the speed of the other skater is 0.84 m/s. What is this skater s mass?
Physics Force & Laws Of Motion Level: University
ImpulseIn a typical golf swing the club is in contact with the ball for about 0.0012 s. If the 45 g ball acquires a speed of 73 m/s estimate the magnitude of the force exerted by the club on the ball.
Physics Electromagnetic Waves Level: University
The amplitude of the electric field component of an electromagnetic wave is increased from E to 4E. What is the corresponding change in the intensity of the wave?(a) The intensity is unchanged by the increase in E
(b)The intensity increases by a factor of 16
(c) The intensity increases by a factor of 4
(d) The intensity decreases by a factor of 4
(e) The intensity decreases by a factor of 16
Physics Electromagnetic Waves Level: University
The amplitude of the electric field component of an electromagnetic wave is increased from E to 4E. What is the corresponding change in the intensity of the wave?(a) The intensity is unchanged by the increase in E
(b) The intensity increases by a factor of 16
(c) The intensity increases by a factor of 4
(d) The intensity decreases by a factor of 4
(e) The intensity decreases by a factor of 16`
Physics Alternating Current Level: University
ImpedanceWhen the frequency of an ac circuit is increased at constant coltage the current increases and then decreases. Which combination of elements is most likly to comprise this circuit?
(a) Resistors only
(b) inductors only
(c) Capacitors only
(d) A combination of inductors and resistors
(e) A combination of inductors and capacitors
Physics Alternating Current Level: University
Reactancewhen the frequency of an ac circuit is decreased the current in the circuit increases. Which combination of elements is most likely to comprise the circuit?
(a) Resistors only
(b) Inductors only
(c) Capacitors only
(d) Capacitors and resistors
(e) Inductors and Capacitors
Physics Alternating Current Level: University
A battery is used to drive a circuit. After a certain amount of time the current is zero amperes. when the same circuit is drive by an ac generator the current is non-zero and alternates. which combination of elements is most likely to comprise the circuit?(a) resistors only
(b) Inductors only
(c) Capacitors only
(d) A combination of inductors and resistors
(e) A combination of inductors and capacitors
Physics Magnetism,Magnetic Effects Of Current Level: University
Lorentz forceAn electron travels through qa region of space with no acceleration. Which one of the following statements is the best conclusion?
(a) Both E and B must be zero in that region
(b) E must be zero, but B might be non- zero in that region
(c) B must B might both be non-zero but they must be mutually perpendicular
(d) B must be zero but E might be non-zero in that region
(e) E and B might both be non- Zero but they must point in opposite directions.
Physics Magnetism,Magnetic Effects Of Current Level: University
Torque on current coilA circular coil consists of 5 loops each of diameter 1.0m. The coil is placed in an external magnetic field of 0.5T. When the coil carries a current of 4.0A a torque of magnitude 3.93N * m acts on it. Determine the angle between the normal to the plane of the coil and the direction of the magnetic field.
(a) 0
(b) 30
(c) 45
(d) 60
(e) 90
Physics Current Electricity Level: University
Heating effect of currentThe current through a certain heater wire is found to be fairly independent of its temperrature. If the current through the heater wire is doubled, the amount of energy delivered by the heater in a given time interval will
(a) Increase by a factor of two.
(b) Decrease by a factor of two
(c)Increase by a factor of four
(d)Decrease by a factor of four
(e) Increase by a factor of eight
Physics Units Level: University
MeasurementsWhich one of the following combinations of units is equivalent to the ohm?
(a) V/C
(b) A/J
(c) J/s
(d) J* s/C^2
(e) W/A
Physics Modern Physics Level: University
AtomFind the energy for a hydrogen atom in the stationary state n=4.
