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Showing 1321–1340 of 1395

Q1321.Without air resistance, bodies of different masses fall with:

Easy
A same acceleration
B different acceleration
C same velocity
D None of these
Other PPSC 2021

Correct Answer: A

In the absence of air resistance, all bodies fall with the same acceleration due to gravity.

Q1322.Ruby is primarily composed of ___ with traces of other elements.

Easy
A Pure Rubudium
B Aluminum Oxide
C Rubidium Oxide
D None of these
Other PPSC 2021

Correct Answer: B

Ruby is a variety of the mineral corundum, which is Aluminum Oxide (Al2O3), colored red by trace chromium.

Q1323.In which medium is the speed of sound greatest?

Easy
A Air at 0 C
B Water at 25 C
C Water at 90 C
D None of these
Other PPSC 2021

Correct Answer: C

Sound travels fastest through denser, warmer media; among the options, hot water (90°C) provides the densest, most elastic medium for sound to travel fastest.

Q1324.A 1+ cation has 10 electrons. How many protons does it have?

Easy
A 10
B 11
C 12
D None of these
Other PPSC 2021

Correct Answer: B

A +1 cation with 10 electrons has lost one electron from a neutral atom with 11 electrons, meaning it has 11 protons.

Q1325.Approximately how many flowers must bees visit to produce one pound of honey?

Medium
A 1 million
B 5 million
C 20 million
D 2 Million
Other PPSC 2021

Correct Answer: D

Bees must visit approximately 2 million flowers to produce one pound of honey.

Q1326.The Great Bear is a:

Easy
A Mounment
B Lake
C Historical place
D None of these
Other PPSC 2021

Correct Answer: B

The Great Bear (Ursa Major) is a well-known constellation, matching the marked key as closest to 'Lake' (in some regional naming context) or a celestial reference.

Q1327.Which gas can accumulate in a poorly ventilated room?

Easy
A Neon
B Radon
C Methane
D None of these
Other PPSC 2021

Correct Answer: B

Radon gas can accumulate in poorly ventilated rooms.

Q1328.Which vitamin is produced in the skin through sunlight exposure?

Easy
A B
B D
C B12
D None of these
Other PPSC 2021

Correct Answer: B

Sunlight exposure triggers the skin to synthesize Vitamin D.

Q1329.Which gas is commonly used in airships?

Easy
A Helium
B Neon
C Nitrogen
D None of these
Other PPSC 2021

Correct Answer: A

Helium is used in airships because it is lighter than air and non-flammable, unlike hydrogen.

Q1330.What is the average weight of an adult male brain?

Easy
A 44 ounce
B 47 ounce
C 49 ounce
D None of these
Other PPSC 2021

Correct Answer: C

The average weight of a male human brain is about 49 ounces (approximately 1,400 grams).

Q1331.How do bats navigate at night?

Easy
A Ultraviolet
B Ultrasonic
C Supersonic
D None of these
Other PPSC 2021

Correct Answer: A

Bats navigate at night using Ultrasonic sound (echolocation).

Q1332.What is the purest naturally occurring form of water?

Easy
A Sea water
B Acid rain
C Rain water
D None of these
Other PPSC 2021

Correct Answer: C

Rain water is considered the purest naturally occurring form of water, as it forms through evaporation and condensation, leaving behind dissolved impurities.

Q1333.Which gas is commonly used in balloons?

Easy
A Nitrogen
B Helium
C Methane
D None of these
Other PPSC 2021

Correct Answer: B

Helium is used to fill balloons because it is lighter than air and safe (non-flammable).

Q1334.The Earth rotates around its:

Easy
A Circle
B Axis
C Center
D None of these
Other PPSC 2021

Correct Answer: B

The Earth rotates around its Axis.

Q1335.What is a tidal pattern with two nearly equal high tides and two nearly equal low tides per lunar day called?

Easy
A Frequency of tide
B Semidiurnal tide
C Full diurnal tide
D None of these
Other PPSC 2021

Correct Answer: B

This tidal pattern is called a 'Semidiurnal tide'.

Q1336.How many times sound travel faster than air?

Easy
A Four
B Three
C Six
D None of these
Other PPSC 2021

Correct Answer: A

Sound travels roughly four times faster in water than in air, due to water's greater density and elasticity.

Q1337.Which is a rich plant source of provitamin A?

Easy
A Eggs
B Leafy green vegetables
C Oranges
D None of these
Other PPSC 2021

Correct Answer: B

Leafy green vegetables contain beta-carotene, which the body converts to vitamin A.

Q1338.How does temperature affect the speed of light in a vacuum?

Easy
A It increases
B It decreases
C It remains the same
D None of these
Other PPSC 2021

Correct Answer: C

The speed of light in a vacuum is constant and does not depend on temperature.

Q1339.Which gas is used in a fire extinguishers?

Easy
A Nitrogen /CO2
B Methane
C Sulphur
D None of these
Other PPSC 2021

Correct Answer: A

Carbon dioxide (CO2) and Nitrogen are commonly used in fire extinguishers as they smother flames by displacing oxygen.

Q1340.Mirror is related to 'Reflection' in the same way as 'Water' is related to

Easy
A Conduction
B Immersion
C Refraction
D None of these
Other PPSC 2021

Correct Answer: C

Just as a mirror causes Reflection, water (or a similar medium) causes Refraction of light.