UI Physics 2011/2012 Past Questions

Practice each question, then open it to see the full details.

Which of the following optical instruments does not depend on the use of plane mirrors?

A.Kaleidoscope
B.Simple microscope
C.Sextant
D.Simple periscope

Which of the following statements supports the assumption that light travels in straight lines?

A.light can be diffracted
B.light can be reflected
C.a source of light produces interferences patterns on a suitably placed screen
D.a source of light produces distinct shadows of opaque objects

Which of the following is correct about nuclear fission? It is:

A.the splitting of a heavy nucleus into two or more lighter particles
B.an agent used to slow down neutrons in a controlled atomic chain reaction
C.combing light atomic nuclei to form heavy
D.the spontaneous disintegration occuring in the nucleus of certain atoms

A light energy E falls on a metal and the electrons with a maximum kinetic energy of 0.2eV are ejected. If the work function of the metal is 0.3eV, what is the value of E?

A.0.10eV
B.0.06eV
C.0.50eV
D.1.50eV

A nucleus is unstable if

A.it has two or more isotopes
B.its binding energy is not sufficient to hold nuclear particles together.
C.it is very light with very low density
D.it has no significant mass

A radioactive substance has a half life of 4 years. If its activity today is 200 dps, its activity in 8 years from today is

A.50 dps
B.25 dps
C.20 dps
D.10 dps

A substance has a half-life of 3min. After 6min, the count rate was observed to be 400.What was its count rate at zero time?

A.2400
B.200
C.1200
D.1600

An element and its isotopes differ only in the number of

A.electrons
B.neutrons
C.protons
D.irons

Complete the following sentence: When electrons from a heated filament accelerate through vacuum toward a positive plate,

A.only an electric field will be produced.
B.only a magnetic field will be produced.
C.electromagnetic waves will be produced.
D.longitudinal waves will be produced

Radioactive elements are

A.chemically reactive elements
B.noble elements
C.rare earth elements
D.elements that spontaneously emit radiation

The following radiations are electrically neutral except

A.a-rays
B.y-rays
C.x- rays
D.neutrons

Upon which one of the following parameters does the energy of a photon depend?

A.mass
B.polarization
C.amplitude
D.frequency

Which of the following is NOT true about cathode ray?

A.It moves in a straight line
B.It causes fluorescence
C.It possesses a negative charge
D.It can produce -particles

Who proposed the planetary model of the nucleus?

A.J. J Thomson
B.Albert Einstein
C.Ernest Rutherford
D.Marie Curie

X- rays cannot be used

A.to take photographs of bone structure in the body
B.to detect finger prints
C.to detect flaws in metal castings
D.to detect alterations to works of art

1 farad is equivalent to:

A.1 coulomb/volt
B.1 volt/coulomb
C.1 joules/coulomb
D.1 ampere/sec. (E) volts per unit charge

A 0 - 10mA galvanometer with a coil resistance of 30 ohm can be converted to a 0 - 10A ammeter by using

A.0.03ohm series resistor
B.9.99ohm shunt resistor
C.0.03ohm shunt resistor
D.9.99ohm series resistor

A battery has an internal resistance of 4 and an emf of 12V. The terminal voltage when a load of 20Ω is connected across it is:

A.4
B.10 V
C.20 V
D.2V

A conducting sphere has a net charge of -4.8 x 10^-17C. What is the approximate number of excess electrons on the sphere if the fundamental natural charge is -1.6 x 10^-19C?

A.100
B.300
C.200
D.400

A magnet cannot be demagnetized by

A.heating
B.hammering
C.chemical treatment
D.the use of solenoid through which an alternating current is flowing

An a.c voltage is connected to an RLC series circuit of resistance 5 0, inductance 3mH and a capacitance of 0.05 F. Calculate the resonance frequency.

A.11.0 kHz
B.12.0 kHz
C.13.0 kHz
D.14.0 kHz

An electric heater converts 1KJ of electrical energy to heat energy every 2 second with 100% efficiency. The power produced is

A.0.5 KW
B.2 KW
C.1KW
D.10W

Complete the following statement: The electromotive force is

A.the maximum potential difference between the terminals of a battery.
B.the force that accelerates electrons through a wire when a battery is connected to it.
C.the force that accelerates protons through a wire when a battery is connected to it.
D.the maximum capacitance between the terminals of a battery

If a charged body is moving in a circle on a horizontal plane, what is the general direction of the resulting magnetic field?

A.In the plane of the circle.
B.At an angle 45° to the plane of motion.
C.Along the perpendicular axis through the center of the circle.
D.Along the tangent to the circle

If a resistor is halved in magnitude and the potential across it is tripled, then the ratio of the old current to the new current is

A.1:3
B.3:1
C.6:1
D.1:6