General Knowledge (NDA/NA SOLVED PAPER 2023-I) (Part – B) (51 to 100)

Total Questions: 50

1. Two identical spring balances S₁ and S₂ are connected one after the other and are held vertically as shown in the figure. A mass of 10 kg is hanging from S₂. If the readings on S₁ and S₂ are W₁ and W₂ respectively, then:

Correct Answer: (d) W₁ = 10kg and W₂ = 10kg
Solution:

2. A stone is thrown horizontally from the top of a 20 m high building with a speed of 12 m/s. It hits the ground at a distance R from the building. Taking g = 10 m/s² and neglecting air resistance will give:

Correct Answer: (c) R = 24m
Solution:

3. A sphere of volume V is made of a material with lower density than water. While on Earth, it floats on water with its volume f₁V (f₁ < 1) submerged. On the other hand, on a spaceship accelerating with acceleration a < g (g is the acceleration due to gravity on Earth) in outer space, its submerged volume in water is f₂V. Then :

Correct Answer: (a)
Solution:(a)

4. Two identical containers X and Y are connected at the bottom by a thin tube of negligible volume. The tube has a valve in it, as shown in the figure. Initially container X has a liquid filled up to height h in it and container Y is empty. When the valve is opened, both containers have equal amount of liquid in equilibrium. If the initial (before the valve is opened) potential energy of the liquid is P₁ and the final potential energy is P₂ then:

Correct Answer: (c) P₁ = 2P₂
Solution:Consider the mass of all the liquid is m, then mass of containers x and y is m/2. After opening the value, the liquid will be divided equally in container x and as shown in below.

Container Y is same placed before and after condition. So gravitational potential energy due to container y does not changed.
Initial potential energy of the liquid p₁ = (mgh)/2
Final potential energy of the liquid p₂
= m/2 × g × h/2 = (mgh)/4
p₁/p₂ = (mgh)/2 × 4/(mgh)
p₁ = 2p₂

5. A particle is moving in a circle of radius R with a constant speed v. Its average acceleration over the time when it moves over half the circle is:

Correct Answer: (c) 2v²/πR
Solution:

6. Two forces of 5.0 N each are acting on a point mass. If the angle between the forces is 60°, then the net force acting on the point mass has magnitude close to:

Correct Answer: (a) 8.6 N
Solution:

7. Which one of the following is not an igneous rock??

Correct Answer: (b) Slate
Solution:Igneous rocks form when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface.
Example of igneous rocks includes andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff. Slate is a type of metamorphic rock which is formed when shale gets metamorphosed.

8. Which of the following statements is/are correct?

1. Hypocenter is the point on the surface of the Earth, nearest to the focus.
2. Velocity of earthquake waves is higher in denser materials.
3. P waves move faster and are the first to arrive at the surface of the Earth.
Select the correct answer using the code given below:

Correct Answer: (b) 2 and 3
Solution:The subsurface location (focus) at which the energy of an earthquake is released is known as hypocentre.
Earthquakes generally occur at depths less than about 30 km.
P waves are the fastest body waves and arrive at stations before the S waves, or secondary waves. Their velocity in the crust varies between 5.0 and 7.0 km/s. Seismic waves move more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid.

9. In terms of geological time scale, the quaternary period consists of two epochs. They are:

Correct Answer: (b) Holocene and Pleistocene
Solution:The Quaternary Period is divided into two epochs, Holocene and Pleistocene. Holocene is the youngest epoch of Quaternary period while Pleistocene is the oldest.

10. Which one of the following is the correct sequence of arrangement of the given planets is descending order of their density (in gm/cm³)?

Correct Answer: (c) Earth > Venus > Jupiter > Saturn
Solution:Earth > Venus > Jupiter> Saturn
PlanetAverage Density (gm/cm³)
Mercury5.4
Venus5.2
Earth5.5
Mars3.9
Jupiter1.3
Saturn0.7
Uranus1.3
Neptune1.6