Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology

Many houses have an electricity meter that is read so that the cost of the electricity used by the customer can be calculated. What does the electric meter record?

  1. charge

  2. energy used

  3. power

  4. current
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Electricity meters measure the total energy consumed by a household, typically in kilowatt-hours (kWh). This is then used to calculate the cost. They do not measure charge (coulombs), power (watts), or current (amps) directly - these are instantaneous values.

Multiple choice general knowledge science & technology

The lengths of mercury thread in the stem of a mercury thermometer are given in three situations. length in melting ice = 20 mm length in steam above boiling water = 170 mm length in liquid X = 50 mm What is the temperature of liquid X in degrees centigrade?

  1. 40 degree C

  2. 30 degree C

  3. 20 degree C

  4. 10 degree C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using the linear scale formula: $T = \frac{L_x - L_{ice}}{L_{steam} - L_{ice}} \times 100$. Here, $\frac{50 - 20}{170 - 20} \times 100 = \frac{30}{150} \times 100 = 0.2 \times 100 = 20$. Thus, the temperature is 20 degrees Celsius.

Multiple choice general knowledge science & technology

What is emitted by the hot metal filament in a cathode ray tube?

  1. protons

  2. neutrons

  3. electrons

  4. x-rays
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a cathode ray tube, the hot metal filament (cathode) emits electrons through a process called thermionic emission. These electrons are then accelerated toward the anode, forming the cathode ray. Protons and neutrons remain in the nucleus, and X-rays are produced when electrons strike the target, not emitted by the filament.

Multiple choice general knowledge science & technology

An object A of mass 2kg is moving with a velocity of 3m/s and collides head on with an object B of mass 1kg in the opposite direction with a velicity of 4m/s. after collision both objects stick, so that they move with a common velocity (v). Calculate v?

  1. 2/3 m/s

  2. 1/3 m/s

  3. 4/3 m/s

  4. 5/3 m/s
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Using conservation of momentum: Initial momentum = (2kg × 3m/s) + (1kg × -4m/s) = 6 - 4 = 2 kg m/s. After collision, combined mass = 3kg moving with velocity v. So 3v = 2, giving v = 2/3 m/s. The negative sign for object B's velocity indicates opposite direction.

Multiple choice general knowledge science & technology

Which material is the best absorber of infra-red radiation?

  1. white paper

  2. dark anumal fur

  3. shiny metal

  4. window glass
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Dark animal fur is the best absorber of infrared radiation because dark colors absorb more radiation, while white or shiny surfaces reflect it. This is why animals in cold climates often have dark fur. White paper reflects, shiny metal is highly reflective, and window glass is transparent to most infrared.

Multiple choice general knowledge science & technology

What causes a moving body to resist a change in its state of motion?

  1. acceleration

  2. velocity

  3. displacement

  4. inertia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Inertia is the property of matter that causes a moving body to resist changes in its state of motion. It is directly proportional to mass - larger objects have more inertia. Velocity, acceleration, and displacement describe motion but don't explain resistance to change.

Multiple choice general knowledge science & technology

• Man Wrinkle spent one-fourth of his life as a boy, one-eighth as a youth, and one-half as an active man. If Man Wrinkle spent 12 years as an old man, then how many years did he spend as an active man?

  1. 48

  2. 96

  3. 24

  4. 32
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let total life = x years. Boy = x/4, youth = x/8, active man = x/2, old man = 12. Sum: x/4 + x/8 + x/2 + 12 = x. Common denominator 8: (2x + x + 4x)/8 + 12 = x → 7x/8 + 12 = x → 12 = x/8 → x = 96. Active man period = x/2 = 96/2 = 48 years. Verify: 24 + 12 + 48 + 12 = 96 ✓

Multiple choice general knowledge science & technology

• Mr. Brown has 6 black gloves and 12 brown gloves in his closet. He blindly picks up some gloves from the closet. What is the minimum number of gloves Mr. Brown will have to pick to be certain to find a pair of gloves of the same color?

  1. 7

  2. 3

  3. 13

  4. 9
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Mr. Brown has 6 black gloves and 12 brown gloves (18 total, 2 colors). Worst case: picking 1 glove of each color gives no pair. With only 2 colors available, by the pigeonhole principle, picking 3 gloves guarantees at least 2 are same color (either 2 black or 2 brown). This works regardless of specific quantities - you only need to know there are 2 colors.

Multiple choice general knowledge science & technology

Suppose 8 monkeys take 8 minutes to eat 8 bananas How many monkeys would it take to eat 80 bananas in 80 minutes?

  1. 8

  2. 10

  3. 80

  4. 1
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Each monkey eats 1 banana in 8 minutes (8 monkeys : 8 bananas : 8 minutes = 1:1:1 ratio). To eat 80 bananas in 80 minutes, each monkey still eats at 1 banana per 8 minutes rate. In 80 minutes, one monkey eats 10 bananas. So 8 monkeys × 10 bananas each = 80 bananas in 80 minutes. The rate doesn't change with scale.

Multiple choice general knowledge science & technology

A 30" x 30" square metal plate needs to be fixed by a carpenter on to a wooden board. The carpenter uses nails all along the edges of the square such that there are 31 nails on each side of the square. Each nail is at the same distance from the neighboring nails. How many nails does the carpenter use?

  1. 124

  2. 118

  3. 116

  4. 120
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is a classic counting problem. A 30×30 inch square with 31 nails on each side. Corner nails are shared between adjacent sides. Total = 4 corners + (31-2) nails on each of 4 sides = 4 + 29×4 = 4 + 116 = 120. Common mistake is calculating 31×4 = 124 (double-counting corners) or 30×4 = 120 (assuming 30 nails per side, not 31).