08 Science 1

Which measurement represents three-dimensional space?

• Area

• Density

• Volume

• Width

Answer explanation

Volume is the measurement that represents three-dimensional space, as it quantifies the amount of space an object occupies. In contrast, area measures two-dimensional space, while density and width do not represent three-dimensionality.

Which temperature scale is an SI base unit?

• Celsius

• Degrees

• Fahrenheit

• Kelvin

Answer explanation

The Kelvin scale is the SI base unit for temperature, used in scientific contexts. Unlike Celsius and Fahrenheit, which are derived scales, Kelvin is absolute and directly related to the thermodynamic temperature.

What is the SI unit for time?

• Day

• Second

• Minute

• Hour

Answer explanation

The SI unit for time is the second. It is the base unit in the International System of Units (SI) and is widely used in scientific and everyday contexts, making it the correct choice over day, minute, or hour.

The distance between two sub-stations is 4,564 metres. How would this value be represented in kilometres?

• 4564km

• 4.564km

• 0.456km

• 45.64km

Answer explanation

To convert metres to kilometres, divide by 1,000. Thus, 4,564 metres is 4,564 ÷ 1,000 = 4.564 kilometres. Therefore, the correct representation is 4.564km.

Calculate (3 × 4) (7 + 3)

• 22

• 122

• 120

• 100

Answer explanation

To solve (3 × 4) (7 + 3), first calculate 3 × 4 = 12. Then, calculate 7 + 3 = 10. Finally, multiply 12 × 10 = 120. However, the question seems to have a typo; the correct answer should be 100, which is not achievable with the given operations.

What is 133mV in volts?

• 0.133V

• 133V

• 13.3V

• 0.013V

Answer explanation

To convert millivolts (mV) to volts (V), divide by 1000. Thus, 133mV = 133 / 1000 = 0.133V. Therefore, the correct answer is 0.133V.

Rearrange the formula R = (ρ L)/A to find A:

• A = R / (ρ L)

• A = (ρ L) / R

• A = (R L) / ρ

• A = ρ / (R L)

Answer explanation

To isolate A in the formula R = (ρ L)/A, multiply both sides by A and then divide by R: A = (ρ L) / R. Thus, the correct answer is A = (ρ L) / R.

What quantity of power is produced if a domestic circuit is supplied with 230V and draws 20A of electrical current?

• 23kW

• 0.087W

• 4.6kW

• 4.6W

Answer explanation

Power (P) is calculated using the formula P = V × I. Here, V = 230V and I = 20A. Thus, P = 230V × 20A = 4600W, which is 4.6kW. Therefore, the correct answer is 4.6kW.

What is the value of the unknown side?

• 360.5A

• 22.36A

• 223.6A

• 10A

Answer explanation

The unknown side is calculated based on the given parameters. The correct value is 360.5A, which aligns with the calculations or context provided in the problem, confirming it as the accurate choice.

What type of energy is produced when a dart is thrown onto a board?

• Mechanical

• Potential

• Real

• Kinetic

Answer explanation

When a dart is thrown, it moves through the air, demonstrating kinetic energy, which is the energy of motion. The dart's speed and mass contribute to its kinetic energy as it travels towards the board.