A proton of wavelength \(\lambda_o\) is emitted when an electron in an atom makes a transition from a level of energy 2E. If the electron transits from \(\frac{4}{3}E_k\) to E level, determine the wavelength of the photon that would be emitted
- A. 3\(\lambda_o\)
- B. 2\(\lambda_o\)
- C. \(\frac{3}{4}\)\(\lambda_o\)
- D. \(\frac{1}{3}\)\(\lambda_o\)
In which of the following transitions is the largest quantum of energy liberated by an hydrogen atom when the electron changes energy levels? [n is the quantum number]
- A. n = 2 to n = 1
- B. n = 1 to n = 2
- C. n = 2 to n = 3
- D. n = 3 to n = 2
Absorption line spectra exhibited by atoms is a result of
- A. change in the kinetic energy of a movimg atom
- B. instability of the nucleons
- C. excitation of an electron in the atom
- D. transition of an electron from a higher to a lower energy level
A material of mass 1.0 x 10-2kg undergoes a fission process which decreases its mass by 0.02 percent. Calculate the amount of energy released in the process. (c = 3.0 x 108ms-1)
- A. 1.8 x 1020J
- B. 1.8 x 1013J
- C. 1.8 x 1011J
- D. 1.8 x 1010J
The half life of a radioactive substance is 14 days. If 48g of this substance is stored, after how many days will 1.5g of the original substance remain?
- A. 84 days
- B. 70 days
- C. 56 days
- D. 40 days
A nuclide \(^{202}_{84} Y\) emits in succession an \(\alpha-particle\) and a \(\beta-particle\). The atomic number of the resulting nuclide is
- A. 198
- B. 83
- C. 82
- D. 80
Borh’s theory provides evidence for the
- A. structure of the atom
- B. positive charge of an electron
- C. existence of energy level in the atom
- D. positive charge on a proton
calculate the inductance of an inductor whose reactance is one ohm at 50 Hz.
- A. 2.00 x 10-2H
- B. 6.36 x 10-2H
- C. 3.18 x 10-3H
- D. 4.55 x 10-2H
An inductor of inductance 10H carries a current of 0.2A. Calculate the energy stored in the inductor
- A. 0.1J
- B. 0.2J
- C. 1.0J
- D. 2.0J
If a bar magnet is accidentally broken into three pieces as shown in the diagram above, the polarities of P and Q respectively are
- A. S and S
- B. N and S
- C. N and N
- D. S and N
A device used to prevent wearing away of the make and-brake contacts of an induction coil is called a\an
- A. fuse
- B. electroscope
- C. resistor
- D. capacitor
The region around a magnet in which the magnetic influence is experienced is called
- A. magnetic flux
- B. magnetic field
- C. magnetic meridian
- D. magnetic declination
An immersion heater is rated 120W. How long does it take the heater to raise the temperature of 1.2kg of water by 15oC. (Assuming heat lost to the surrounding is negligible. Specific heat capacity of water = 4200 Jkg-1K-1C)
- A. 65.0 minutes
- B. 60.0 minutes
- C. 52.5 minutes
- D. 10.5 minutes
In the diagram above, the current passing through the 6\(\Omega\) resistor is 1.5A. Calculate the current in the 3\(\Omega\) resistor
- A. 1.20A
- B. 0.90A
- C. 0.75A
- D. 0.60A
The capacitance of a parallel-plate capacitor is increased by making the area of the plates
- A. small and their seperation large
- B. large and their seperation small
- C. and their seperation small
- D. and their seperation equal
An object is situated within the Earth’s gravitational field. Which of the following factor does not affect the acceleration of free fall g?
- A. the distance of the object from the centre of the earth
- B. the latitude of the earth on which the object is situated
- C. rotation of the earth
- D. the mass of the object
the factor which enables the ear to distinguish between a note played on different instruments is the
- A. pitch
- B. speed
- C. harmonics
- D. loudness
loudness increases as a vibrating tuning fork is brought nearer the end of a pipe containing air column due to
- A. resonance
- B. echo
- C. reverberation
- D. diffraction
A turning fork of frequency 600Hz is sounded over a closed resonance tube. If the first and second resonant positions are 0.130m and 0.413m respectively, calculate the speed of sound in air
- A. 508.4ms-1
- B. 480.0ms-1
- C. 339.6ms-1
- D. 169.8ms-1
In which of the following media does sound travel faster?
- A. water
- B. brass
- C. air
- D. wood
When white light passes through a triangular glass prism, there is dispersion because of
- A. diffraction of light
- B. polarisation of light
- C. the difference in speed of the components of light
- D. the interference of light waves in glass