Which of the following properties is found only in ferromagnetic materials ?

Correct Answer: Silver

Explanation:

silver is the best conductor of electricity.

When compared to remaining 3 metals, as Silver having more number of free electrons in its valency shell it is the good conductor of electricity.

Conductors Thermal Conductivity @ 25degree C

Silver --- 429
Copper --- 401
Gold --- 310
Aluminium --- 250

Correct Answer: FALSE

Explanation:

False. The ankle is not the third-class lever in the body.

 

Levers are typically labeled as first class, second class, or third class. All three types are found in the body, but most levers in the human body are third class.

First-class levers in the human body are rare and have the axis (fulcrum) located between the weight (resistance) and the force. One example is the joint between the head and the first vertebra.

In a second-class lever, the weight (resistance) is located between the axis (fulcrum) and the force. An example of a second-class lever in the human body is found in the lower leg when someone stands on tiptoes

In a third-class lever, the most common in the human body, force is applied between the resistance (weight) and the axis (fulcrum). There are numerous third-class levers in the human body; one example can be illustrated in the elbow joint.

Correct Answer: Violet

Explanation:

In VIBGYOR. It has colors ordered from highest to lowest frequency.

 

              Violet > Indigo > Blue > Green > Yellow > Orange > Red

 

That says Violet has the highest frequency.

We know, Speed of light = Frequency x Wavelength

=> As frequeny is inversely proportional to wavelength i.e, as frequwncy goes high wavelength goes down.

 

So, the violet color has the highest frequency.

Correct Answer: detecting and locating the position of objects such as Aeroplanes

Explanation:

RADAR - RAdio Detection And Ranging.

A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. 

 

Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

 

Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.

Correct Answer: A Contact force is a force applied to a body by another body that is in contact with it Contact force acts on a point of direct contact between the two objects This force can either be continuous as a continuous force or can be momentary in the form of an impulse Contact force is governed by Newton?s Laws Examples :: Contact force is responsible for most of the interactions we experience in the daily life 1 Writing your name with a pen, pushing a car up a hill, lifting an object, etc 2 Kicking a ball, hammering a nail, etc are some of the everyday examples where contact forces are at work In the first case, the force is continuously applied by the person on the car or pen or an object while in the second case the force is delivered in a short impulse Contact forces are often decomposed into orthogonal components one perpendicular to the surface in contact called the normal force, and one parallel to the surface in contact, called the friction force

Correct Answer: mud

Explanation:

Among the given options, mud is not an aerosol.

 

An aerosol is a suspension of fine solid particles or liquid droplets, in the air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog, dust, forest exudates and geyser steam. Examples of anthropogenic aerosols are haze, particulate air pollutants, and smoke.

Correct Answer: Resistivity : Resistivity is a measure of the resistance to the flow of electrons Conductivity : Conductivity is just the inverse of resistivity, ? = 1/?, where ? is conductivity and ? is resistivity Example: Think of a pipe and water, the bigger the pipe, the easier water can flow and thus the lower the resistance

Correct Answer: Proton

Explanation:

Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus.

Correct Answer: PWC refers to Personal Water Crafts To control steering on a PWC, the most needed requirement is to have power in which will allows the one using it to control the engine for it to stop or for it to move Without power, the person using it could be out of balance or fail to start the engine This is the basic requirement because even though it is shut off or the engine is off, the PWC is still on and it could still move without proper knowledge of the engine

Correct Answer: Glass

Explanation:

Sound is a mechanical vibration and needs a medium for propagation. The higher the density of the medium, the faster the sound travels. So, sound cannot travel through vacuum.

 

As the sound travels faster in solids than liquids and gases, sound travels faster in the glass than Air and water.