OS Quiz to Win

Anna notices that the ratio of boys to the number of girls in her class is 7:8. If there are 75 students in his class, how many of them are boys?

• 35

• 25

• 40

• 30

• 50

Which of the following has the least modulus of elasticity?

• steel

• copper

• glass

• aluminum

• bronze

In an electric company, the probability of passing an IQ test is 0.75. If ten applicants took the test, what is the theoretical standard deviation of the group? Express your answer with three (3) decimal places.

What is the size in square millimeter (mm2) is the cable 300 MCM size?

• 163

• 144

• 127

• 132

• 152

An object travels at a constant speed of 10 m/s for 10 s. During the next 5 s, it accelerates uniformly to 20 m/s. What is the total distance travelled by the object?

• 150 m

• 175 m

• 200 m

• 250 m

• 300 m

A table-tennis ball has a diameter of 3.80 cm and an average density of 0.0840 g/cm3. What force, in dynes, is required to hold it completely submerged under water? Use g = 980.66 cm/s^2. Express your answer to the nearest whole number.

The speed armature current characteristics of a d.c. series motor is

• Rectangular hyperbola

• Linear

• Parabolic

• Parabolic till saturation then linear

How many diagonals are there in a polygon with 20 sides?

A 3 phase, wye connected, wound rotor synchronous generator rated at 10 kVA, 230 volts has a synchronous reactance of 1.2 ohms/phase and an armature resistance of 0.5 ohms/phase. What is the percent voltage regulation at full load with an 80% leading power factor?

• -0.92%

• -5.14%

• -3.08%

• -3.91%

• -2.67%

A piston cylinder device initially contains 0.6 m^3 of air at 120 kPa and 80°C. Determine the work done if the air is compressed isothermally to a final volume of 0.25 m^3.

• –68 kJ

• –78 kJ

• –73 kJ

• –63 kJ

• None of the choices