Defence Research & Development Organisation Scientist Interview Questions and Answers

Wind tunnels are used to study the effects of air on objects. Materials and their properties play a crucial role in wind tunnel experiments.

• Wind tunnels are used to simulate the flow of air around objects, allowing scientists to study aerodynamics.

• Different materials have different properties that can affect the results of wind tunnel experiments.

• Materials with low drag coefficients, such as smooth metals, are often us...read more

Modes of vibrations of beans refer to the different ways in which beans can oscillate or vibrate.

• Beans can vibrate in different modes depending on their shape, size, and material properties.

• Some common modes of vibrations in beans include bending, twisting, and radial vibrations.

• The mode of vibration affects the frequency, amplitude, and pattern of the bean's oscillation.

• Understanding the modes of vibrations in beans c...read more

There are several types of counters that can be used to design a divide by 5 counter.

• Ripple counter

• Synchronous counter

• Johnson counter

• Ring counter

There are three laws of thermodynamics. Each law has specific applications. dB Amp is not related to thermodynamics.

• The first law of thermodynamics, also known as the law of energy conservation, states that energy cannot be created or destroyed, only transferred or transformed.

• The second law of thermodynamics states that the entropy of an isolated system always increases over time.

• The third law of thermodynamics states...read more

Spark plug ignites fuel-air mixture in IC engines. DTSI improves combustion efficiency. 2-stroke and 4-stroke engines differ in number of strokes per cycle.

• Spark plug ignites the fuel-air mixture in the combustion chamber

• DTSI (Digital Twin Spark Ignition) is a technology used to improve combustion efficiency by using two spark plugs

• 2-stroke engines complete one power stroke in two strokes of the piston, while 4-stroke ...read more

Humidity ratio is measured using two types of instruments: psychrometers and hygrometers.

• Psychrometers measure humidity ratio by comparing the readings of two thermometers: a dry-bulb and a wet-bulb thermometer.

• Hygrometers measure humidity ratio using various principles such as electrical resistance, capacitance, or condensation.

• A 1 ton refrigerator refers to the cooling capacity of the refrigerator, which is equivalen...read more

I would like to design electronic components with heat transfer applications.

• I have a strong interest in electronics and how heat can be managed in electronic systems.

• I enjoy working on projects that involve designing and optimizing electronic components for efficient heat dissipation.

• I have experience in conducting thermal analysis and simulations to ensure proper heat transfer in electronic devices.

• I find it fascinat...read more

The choice between Al and Mg for designing depends on the specific requirements and constraints of the project.

• Aluminum (Al) is lightweight, corrosion-resistant, and has good thermal conductivity, making it suitable for applications where weight reduction is important, such as aerospace.

• Magnesium (Mg) is even lighter than aluminum, but it has lower strength and is more prone to corrosion. It is commonly used in automot...read more

A rocket is a vehicle that propels itself through the atmosphere or space, while a missile is a weapon that is guided towards a target.

• Rockets are used for space exploration, satellite launches, and transportation, while missiles are used for military purposes.

• Rockets are typically unmanned and used for peaceful purposes, while missiles are often armed and used for warfare.

• Rockets are designed to carry payloads such as...read more

The minimum temperature of any substance that we could reach and use for practical purposes is absolute zero, which is -273.15 degrees Celsius or 0 Kelvin.

• The minimum temperature is known as absolute zero.

• It is the lowest possible temperature that can be reached.

• At absolute zero, all molecular motion ceases.

• Practical applications include cryogenics and superconductivity.

• Examples of practical uses are in medical imaging