General Knowledge (Part – B : English) Antonyms (NDA/NA SOLVED PAPER 2022-II) (51 to 100)

Total Questions: 50

11. The commercial unit of electrical energy is kilowatt-hour (kWh), which is equal to

Correct Answer: (a) 3.6 × 10⁶J
Solution:One kilowatt-hour is equivalent to a power of 1 kW being used for 1 hour. Or, 1 kWh =1kW × 1hour = 1000 × 3600W.s.
Or, 1kWh = 3.6×10⁶J. (Since, 1W = 1 J/s)

12. Which one of the following statements regarding a current-carrying solenoid is not correct?

Correct Answer: (d) If a soft iron bar is inserted inside the solenoid, the magnetic field remains the same.
Solution:The field lines inside the solenoid are in the form of parallel straight lines. This magnetic field is the same at all points inside the solenoid and therefore the field is uniform inside the solenoid.
A current carrying solenoid behaves like a bar magnet. The magnetic field inside a solenoid is proportional to both the applied current and the number of turns per unit length.
The magnetic field inside a solenoid is proportional to both the applied current and the number of turns per unit length.
When a soft iron core is inserted inside the solenoid then the strength of the magnetic field becomes very large.

13. An object is made of two equal parts by volume; one part has density ρ0 and the other part has density 2ρ 0. What is the average density of the object?

Correct Answer: (b)
Solution:The average density of the object is given by ρT = M / V
Since the object is made up of two equal parts by volume
Hence volume of part 1 and part will be 1/2 V each The density of part 1 is given by, ρo and the density of part 2 is, 2ρo
Let the mass of part 1 is given by, m₁ and the mass of part 2 is, m₂ then, ρo = m₁/ 0.5 V
and, 2ρo = m₂ / 0.5 V
Here, ρT = Total density of the object, M = mass of 7 object, and V volume of object
ρT = M / V = (ml + m₂) / V
= (ρo × 0.5V) + (2ρo× 0.5V) / V
= (3ρo V / 2) / V = (3/2) ρo

14. A pressure cooker cooks food faster by

Correct Answer: (a) increasing the boiling point of water
Solution:The Pressure cooker works like a sealed chamber. As steam builds inside this chamber pressure increases and raises the boiling point of water past 100°C, thereby speeding up the time it takes to boil or steam.

15. Which one of the following wavelengths corresponds to the wavelength of X-rays?

Correct Answer: (d) 1 nm
Solution:X-rays are shorter in wavelength than UV rays and longer than gamma rays. X-rays have a wavelength in the range of 0.01-10 nm.

16. An electric bulb is connected to 220 V generator. The current drawn is 600 mA. What is the power of the bulb?

Correct Answer: (a) 132 W
Solution:The formula for the power supplied is equal to current 7 times the voltage, and shown as P = IV Where P is the Power, I is the Current in Ampere and V is the Voltage in Volt,
Applying the formula, Power will be 0.6A × 220V =132 W

17. When the pitch of sound increases, which one of the following increases?

Correct Answer: (d) Frequency
Solution:Pitch is the sensation of the frequency of an emitted sound. Higher is the frequency higher is the pitch and similarly lower pitch corresponds to lower frequency.

18. Which one of the following is the correct reactivity series with water?

Correct Answer: (a) Zinc > iron > Lead > Copper
Solution:The correct sequence of reactivity with water is, Zinc > Iron Lead> Copper.
Water-reactive substances are those that spontaneously undergo a chemical reaction with water, as they are highly reducing in nature. Examples include alkali metals, lithium through caesium, and alkaline earth metals, magnesium through barium.

19. Which one of the following metals floats in cold water?

Correct Answer: (c) Potassium
Solution:Metals like Calcium and Sodium reacts with cold water. Calcium starts floating on water as the bubbles 80 of hydrogen gas produced during the reaction stick to the surface of the metal and helps in floating.

20. Which one of the following solutions is not capable of conducting electricity?

Correct Answer: (c) Sugar
Solution:Sugar solution do not contain ions in significant numbers and these molecules do not break down into ions when dissolved. Therefore, these solutions cannot carry an electric current.