OAU Physics 2013/2014 Past Questions

Two plane mirrors are inclined at angle 45° one to another. A ray of light has incident angle 20° at the surface of the first mirror. The reflected ray is then incident on the second mirror. Calculate the angle of reflection at the second mirror.

When the length of the string of a simple pendulum is 1 its period is 0.57r seconds. The period when the length is increased to 41 will be

A uniform meter rule AB has a mass 15g. A 30g mass is suspended at the 10.0cm mark, and another 5g mass is suspended at the 65.0cm mark. Calculate the position of the fulcrum that will keep the meter rule balanced horizontally.

A rectangular block measures 40cm x 25cm x 5cm and is made of a material of density 7800kg/m³. Calculate the pressure the block exerts on the floor when it stands on the smallest of its surfaces.

A ship sinks in the bottom of a 250m deep lake. The atmospheric pressure over the lake is 103 x 10⁵Pa. Taking the density of water in the lake to be 1000kg/m³, calculate the pressure exerted on the boat. [acceleration due to gravity = 10m/s²]

Three knives made of steel, plastic and flat wood respectively are placed on a table for an equal amount of time. The steel knife feels coldest to touch because

The coefficient of linear expansion of aluminum is $23 x 10^6K^-1$. If the volume of a pot made with aluminum at temperature $T_0 is V_0$, what will be the change in temperature resulting in a decrease of 0.20% in volume of the pot?

Which of the following features is used to minimize heat loss due to conduction in a thermo - flask?

Which of the following quantities is a scalar quantity?

A car accelerates at 5.0m/s² for 6s, it travels at the speed attained for 20s, and comes to rest after another 4.0s. Calculate the average velocity of the car during the motion

Which of the following quantities is equal to the area under a velocity - time graph?

A 25N force pulls a 2.0kg body up a 30° inclined plane. If the force is parallel to the plane and the body moves up the plane at constant velocity, calculate the magnitude of the frictional force between the body and the plane. [g = 10m/s²]

The process by which a solid changes directly to vapour is called

A resonance tube is 40cm long. The second resonance is head when the tube is three - quarter full. What is the frequency of the tuning fork placed near the mouth of the tube? [velocity of sound in air is 334m/s]

A coin is at the bottom of a bucket filled with a liquid whose refractive index is 1.35. The coin appears to be 12.0cm below the surface of the liquid. Calculate the depth of the liquid.

A 3.0cm object is placed 12.0cm in front of a bi-convex lens of focal length 8.0cm. Calculate the height of the image of the object

To use a milli - ammeter to measure current up to 10A, what connection needs to be made?

Two resistors A and B are made of the same material. The radius of A is three times that of B, and the length of A is half of B. The ratio of the resistance of A to that of B is

Two 2µF capacitors are connected in parallel. The combination is connected in series with a 6 pF capacitor. What is the equivalent capacitor for the combination?

Five 100-watt bulbs are put on for 45 days during which the home - owner is on vacation. If 1KW-hour of electricity costs N7.50, how much does it cost the home - owner?

To convert an a.c. generator to a d.c. generator, one needs to

A student afraid that the substance near him is radioactive places his lecture note between hint and the substance. If truly the substance is radioactive, which of the following radiations can the notebook shield him from?