## Physics Past Questions

The temperature at which the water vapour in the air saturates the air and begins to condense is
• A. melting point
• B. triple point
• C. dew point
• D. melting point
Calcium has a work function of 19 eV with a wavelength of 150 nm. Calculate the maximum energy of a photo electron emitted. (1 eV = 16.1 x 10-19J, h = 6.6 x 10-34Js)
• A. 6.35 Ev
• B. 8.25 cV
• C. 14.60eV
• D. None of above
A boat is passing under a bridge. The deck of the boat is 15m below the bridge. A small package is to be dropped from the bridge onto the deck of the boat is 25m from just below the drop point. What speed is necessary to have the package land in the boat? (g= 9.8ms-2)
• A. 17m/s
• B. 14m/s
• C. 1.7m/s
• D. 4.9m/s
A cigarette lighter in a car is a resistor that, when activated, is connected across the 12 – V battery. If the lighter dissipates 33 W of power, find the current it delivers to the lighter.
• A. 9.90 Ω
• B. 6.60 Ω
• C. 4.36
• D. 17.50Ω
An airplane increases its speed 36 km/h to 360 km/h in 20.0 s. How far does it travel while accelerating.
• A. 4.4 km
• B. 1.1 km
• C. 2.3 km
• D. 1.0 km
Dry air of column length 10 cm is trapped by a pellet of mercury of length 15 cm, with the open end uppermost. When the capillary is inverted the length of the air column increased to 25 cm while that of mercury remained constant. Calculate the atmospheric pressure (in cm of Hg.)
• A. 35 cm Hg
• B. 15 cm Hg
• C. 20 cm Hg
• D. 35 cm Hg
A 3.0cm object is placed 12.0cm in front of bi-convex lens of focal length 8.0cm. Calculate the height of the image of the object.
• A. 3.0cm
• B. 6.0cm
• C. 12.0cm
• D. 24.0cm
If the force on a charge of 0.2 Coulomb in an electric field is 4N, then electric intensity of the field is
• A. 0.8
• B. 0.8N/C
• C. 20.0 N/C
• D. 4.2 N/C
Which of the following statements is not true about a body performing simple harmonic motion?
• A. the linear speed is the product of the angular speed and the radius or amplitude
• B. the linear acceleration is the product of the square of the angular speed and the displacement
• C. frequency is the number of complete revolution per second made by a vibrating body
• D. the S.I unit of amplitude is Hertz (Hz)
A simple pendulum 0.6 long has a period of 1.55, what is the period of a similar pendulum 0.4 long in the same direction
• A. 1.4 √1/3s
• B. 1.5 √1/3s
• C. 2.25s
• D. None of the above