Tag: physics

Questions Related to physics

Which of the following are macroscopic properties?

physics energy management solar power plant production of electricity from solar energy solar equipment solar energy and its applications

  1. texture

  2. phase

  3. viscosity

  4. all of the above

Show answer
Correct Option: D
Explanation:

$Answer:-$ D

Macroscopic properties are qualities that can be seen by the naked eye, and some are relative to the conditions under which a material or element is observed. The three most basic examples of macroscopic properties are color, shape and size.

Other examples of macroscopic properties include texture, phase (solid, liquid or gas), viscosity (if any) and density relative to surroundings (such as oil on water). The properties of an element or material tend to change, even if only slightly, as the conditions change. Examples of changing conditions include how metals tend to glow red when heated to extreme temperatures, how the viscosity of honey decreases with temperature or how the volume of $H _2O$ increases slightly when it freezes.

The reflector of box type solar cooker need not be adjusted with the position of Sun.

physics energy production solar power plant production of electricity from solar energy solar equipment

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: B
Explanation:

Box type solar cooker uses a mirror to trap the sunlight inside the box. It needs to adjusted according to the sunlight so that maximum amount of light is trapped inside the box.

Solar water heater can be used in hospitals for hot water supply.

physics energy production solar power plant production of electricity from solar energy solar equipment

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: A
Explanation:

Answer is A.

Solar water heating is now a mature technology. Wide spread utilization of solar water heaters can reduce a significant portion of the conventional energy being used for heating water in homes, factories and other commercial and institutional establishments. 
Around 60 deg. 80 deg. C temperature can be attained depending on solar radiation, weather conditions and solar collector system efficiency
Hot water for homes, hostels, hotels, hospitals, restaurants, dairies, industries etc. It can be installed on roof-tops, building terrace and open ground where there is no shading, south orientation of collectors and over-head tank above SWH system.
Hence, the given statement is true.

Solar cell is a device which directly converts _______ into electric energy.

physics energy production solar power plant production of electricity from solar energy solar equipment

  1. heat energy

  2. mechanical energy

  3. chemical energy

  4. solar energy

Show answer
Correct Option: D
Explanation:

Solar cell is a device which directly converts solar energy into electric energy.
A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light(sun)  directly into electricity by the photovoltaic effect. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Solar cells are the building blocks of photovoltaic modules, otherwise known as solar panels.

Solar panels can be used in electronic watches.

physics energy production solar power plant production of electricity from solar energy solar equipment

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: A
Explanation:

The statement is true, with upcoming technologies there are solar panels present in watches and these use solar energy to power these watches and for night time there is a small rechargable battery inside the watch,which gets charged enough in day-or during sunlight to power the watch when sunlight is off.

A device when directly converts electric energy into solar energy is called solar cell.

physics energy production solar power plant production of electricity from solar energy solar equipment

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient

Show answer
Correct Option: B
Explanation:

The statement is opposite. Solar cell converts solar energy into electrical energy.

Sclera is a grey-white membrane, which darkens the eye ball from inside.

physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

  1. True

  2. False

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Correct Option: A
Explanation:

Sclera is the white membrane which lines the eyeball. It is the supporting wall of the eye and acts as a protective coating. It is seen in contrast with the iris.

Cilliary muscles in the eye:

physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

  1. hold the eye lens in place

  2. increase or decrease focal length of eye lens.

  3. both (a) and (b)

  4. none of these

Show answer
Correct Option: B
Explanation:

When the ciliary muscle is relaxed, the choroid acts like a spring pulling on the lens via the zonule fibers causing the lens to become flat. When the ciliary muscle contracts, it stretches the choroid, releasing the tension on the lens and the lens becomes thicker. Cilliary muscles in the eye increase or decrease focal length of eye lens.

The nature of image formed on the retina of human eye is:

physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

  1. virtual and erect

  2. virtual and inverted

  3. real and erect

  4. real and inverted

Show answer
Correct Option: D
Explanation:

Human eye lens are convex in nature and form real and inverted images and when the object is kept before the focus point and the centre of the lens it form virtual and erect images. The image formed on retina are real and inverted and further the message sent by the optic nerve are chemical impulses to the brain, which turn them into erect images that we see with our eyes.

Which of the following statements about human eye is NOT true?

physics the human eye and the colourful world human eye and its working what is inside our eyes? human eye and defects of vision

  1. the iris gives a distinct colour to the eye

  2. the yellow spot is extremely sensitive to light

  3. the space between lens and cornea is filled with ciliary muscles

  4. the optic nerves enters the eye near the blind spot

Show answer
Correct Option: C
Explanation:


The space between the cornea and the lens is called the aqueous chamber and filled with thin watery transparent viscous fluid called aqueous humor which supplies nutrients to these structures as well as to the lens. Aqueous humour is produced by the ciliary processes in the posterior chamber and flows into the anterior chamber through the pupil.