Define angle of repose. Is this angle equal to angle of friction?

Q: What is relation connecting absorptive, reflecting and transmitting power of a body?

A: For a given time, the amount of radiations reflected by a body in the form of Thermal radiation to t...

Q: Define stress, strain and Young's modulus of an elastic material.

A: Stress is the ratio of the applied force to a cross section area. It is the force per unit area. The...

Q: When a star has exhausted its hydrogen fuel, it may fuse other nuclear fuels. At temperatures above ...

A: (a)Two alpha articles fuse to produce a nucleus A and gamma ray.

Q: Can the component of a vector be greater than vector itself?

A: Consider a vector R as shown below.

Q: A patient swallows a radiopharmaceutical tagged with phosphorus-32 (P), a ߯ emitter with a half-lif...

A: Formula to calculate the number of electrons emitted is,

Q: What is Magnus effect?

A: Magnus effect can be defined as: 

Q: An AC appliance cord has its live wire and neutral wire separated by 3.00 mm andcarries a 5.00 A cur...

A:

Q: Explain how rain coats become water proof?

A: Rain coats which are water proof will have a water-repellent coating. They are treated with a durabl...

Q: Natural uranium ore contains about 0.720% of the fissile uranium - 235 isotope. Suppose a sample of ...

A: Formula to calculate the number of uranium 235 nuclei is, 

Q: Does the damping force remain constant on a system executing simple harmonic motion?

A: Simple harmonic motion is the simplest example of oscillatory motion. When an object moves to and fr...

Q: Ice is packed in saw dust, Why?

A: Saw dust is a very bad conductor of heat. So, if ice is kept in saw dust, ice will not melt easily.

Q: The slope of ice line in the phase diagram of water is negative . Why?

A: The melting curve or fusion curve of ice/water is very special. It has a negative slope due to the f...

Q: Explain the working of venturimeter.

A: Venturi meter is a device used to measure the rate of flow of fluid through a pipe.

Q: Explain how a cat is able to land on its feet when thrown into air?

A: Step 1The cat uses the concepts of moment of inertia conservation. The cat rotates when it falls.

Q: Name the factors on which the velocity of transverse waves depend? It

A: Velocity of transverse wave is,

Q: A spring balance which is used for long time, shows wrong readings. Why?

A:

Q: When the velocity of a body executing simple harmonic motion is zero its acceleration is not zero. W...

A: The acceleration a of a particle executing a simple harmonic motion is expressed as,

Q: In terms of biological damage, how many rad of heavy ions are equivalent to 100 rad of x - rays?

A: Write the expression for the biological damage caused by the X-rays with a quality factor of 1.

Q: Compare the otto cycle with diesel cycle.

A: The comparison of Otto cycle and Diesel cycle has been shown in the table below:

Q: In the theory of quantum chromodynamics, quarks come in three colors. How would you justify the stat...

A: Quarks come in three colors. However, baryons and mesons are colourless.Each flavor of quark can hav...

Q: What are contact forces? Give examples.

A: contact force is the force which acts between then bodies only when they are physically touched. 

Q: Two simple pendulums of equal length cross each other at mean position. What is their phase differen...

A: Given,Two simple pendulums of equal length cross each other at mean position.Thus, the amplitude and...

Q: What is the difference between the calorie used in physics and Calorie used in nutrition?

A:

Q: What is the mean translational kinetic energy of a perfect gas molecule at temperature T?

A: The absolute temperature of a substance is directly proportional to the mean kinetic energy of its m...

Q: Distinguish between emissive power and spectral emissive power.

A: When any thermal radiation is radiated from a unit surface area, the rate at which it is radiated at...

Q: Describe with a labelled circuit diagram a platinum resistance thermometer. How is it used for measu...

A:

Q: Mercury does not wet glass. Why?

A: The cohesive force between mercury molecules is very much greater than that of the adhesive force be...

Q: What is the volume of a gas at absolute zero of temperature?

A: At absolute zero the volume of an ideal gas would be zero and all molecular motion would cease. In a...

Q: Give advantages and disadvantages of filament pyrometer.

A: Advantages of filament pyrometer are:

Q: Explain Stokes law.

A: According to Stoke’s law, an object moving through a viscous medium will reach maximum velocity call...

Q: Compare the relative merits of mercury and alcohol as a thermometer liquid.

A: Relative merits of mercury and alcohol as a thermometer liquid are: 

Q: Which modulus determines the stretching of a coiled spring?

A: Step 1When a coil spring is stretched or compressed, neither its length nor its volume changes, ther...

Q: In order to minimize neutron leakage from a reactor, the ratio of the surface area to the volume mus...

A: (a) The ratio of the surface area (A) and the volume (V) of the sphere of the radius a can be calcul...

Q: Milk is poured into a cup of tea and is mixed with a spoon. Is this an example of reversible process...

A:  In the reversible process, the initial state of the substance is changed into another state and it ...

Q: The earth without its atmosphere would be inhospitably cold , Why?

A: The sun rays contain infrared radiations.When these rays reach earth’s surface, these are reflected ...

Q: Insulators also contain electrons, but they are not conductors, Why?

A: Insulators consist of atoms having tightly bound electrons. Whereas, conductors have free electrons.

Q: A thermal conductor is heated at one end , What is the theoretical value of its thermal conductivity...

A: Heat flow rate (Q),

Q: the young modulus of a 6 m rod is 186GPa. THe area of cross section of rod is 0.75 x 10^-4  m^2. Cal...

A: Given,

Q: A mass m attached to a spring oscillates with a period of 3 second. If the mass is increased by 2kg,...

A: The time period of the oscillating spring is given by,

Q: Water is slightly warmer at the base of a water fall than at the top, Why?

A: At the top, the water has maximum potential energy. As the water starts to fall, potential energy is...

Q: What is Stefan's constant?

A: The Stefan-Boltzmann constant, symbolized sigma ( ), is a physical constant involving black body rad...

Q: Is it possible to increase the temperature of a gas without adding heat to it? If so how?

A: Yes, it is possible to increase the temperature of a gas without adding heat to it. For an adiabatic...

Q: Particles of camphor move around on the surface of water. Why?

A: The surface tension of water decreases when the impurities are dissolved in it. The camphor is insol...

Q: A photon with an energy of 2.09 GeV creates a p roton – antiproton pair in which the proton has a ki...

A: Formula to find the total kinetic energy after pair production is,

Q: Name the instrument used to demonstrate the higher modes of vibration of a string?

A: The sound produced by stringed musical instruments depends on the tension of the spring, thickness a...

Q: What is the nature of wave produced in a lake, due to an explosion inside the lake?

A: When the explosion takes place in the bottom of the lake, the pressure in the surrounding water incr...

Q: A body cools from 60degree C to 50 degree C , the temperature of surrounding being 25 degree C , Wha...

A: According to Newton’s law of cooling,Substitute the values for cooling a body from 60 degree Celsius...

Q: If the mass attached to a vertical spring is pulled down and left, it oscillates why?

A: When a mass is attached to a vertically suspended spring, the mass stretches the spring to a new equ...

Q: Mention the errors and their correction.

A: Errors in physics are classified into two types:Systematic errorsRandom errors.

Q: A point on a rotating disc is not considered to be simple harmonic ,Why?

A: In simple harmonic motion the acceleration of the body executing the motion will be proportional to ...

Newton’s Third Law of Motion

The horse pulls the cart and the cart pulls the horse in response as per Newton third law. So the big question is, “Don’t the two forces cancel each other? How does the cart accelerate?”