Convex spherical mirrors are preferred to plane mirrors as driving mirrors because

• A. the image produce is upright and clearly visible
• B. it provides a wider field of view
• C. the image produce is errect and diminished
• D. the image produced is not laterally inverted

Which of the following features of an electrostatic line of force is not correct?

• A. it is an imaginary line which a positive charge will describe if it is free to move
• B. the tangent drawn at any point on a curved line of force shows the direction of the electric field intensity at that point
• C. it is sometimes curved
• D. it can cross another line of force in a region of intense electric field

If the kinetic energy of an electron is 100eV, what is the wavelength of the de-Broglie wave associated with it? [h = 6.6 x 10\(^{-34}\) J s, e = 1.6 x 10\(^{19}\)C, m\(_{e}\), = 9.1 x 10\(^{-31}\) kg]

• A. 1.22 x 10\(^{-10}\)m
• B. 4.10 x 10\(^{-10}\)m
• C. 3.90 x 10\(^{-10}\)m
• D. 5.50 x 10\(^{-14}\)m

Light of energy 5eV falls on a metal of work function 3eV and electrons are liberated. The stopping potential is

• A. 1.7V
• B. 2.0V
• C. 8.0V
• D. 15.0V

The radius of a wheel is 30.0 cm and that of its axle is 6.0cm. Calculate the effort required to lift a load of 120.0N using this machine. Assuming 100% efficiency

• A. 600.0N
• B. 40.0N
• C. 24.0N
• D. 20.0N

I. The number of neutrons released exceeds the number that caused the fission.

II. There is loss of mass.

III. Energy is produced.

IV. Smaller nuclei merge to form larger nuclei

Which of the statement above are correct about nuclear fission?

• A) II,III and IV only
• B) I, II and IV only
• C) I,II and III only
• D) I, III and IV only

Find the frequencies of the first three harmonics of a piano string of length 1.5m, if the velocity of the wave on the string is 120m/s

• A. 40Hz, 80Hz, 120Hz
• B. 80Hz, 160Hz, 240Hz
• C. 180Hz, 360Hz, 540Hz
• D. 369Hz, 180Hz, 90Hz

Which of the following obeys ohms laws?

• A. electroytes
• B. metals
• C. diode
• D. glass

Which of the following are the essential parts of an atomic bomb?

• A. Uranium and neutrons
• B. Radium and polonium
• C. Nitrogen and neutrons
• D. ranium and α - particles

When the temperature of a liquid is increased, its surface tension?

• A. increases
• B. decreases
• C. remain constant
• D. increases then decreases