Skip to main content

Light, Shadows And Reflections Quest Time for class VI

Brain Teaser Quest Time For Class 6th Light, Shadows And Reflections

1. How can you determine the length of the shadow of an object?

Ans: We cannot correctly determine the length of the shadow of an object. The length of shadow depends on the angle at which light fall on a body and varies at different time of day. This principal helps us to make sun dial for calculating time.

2. How can you make sundial at home?

Ans: We take a pencil and place it into the whole of the empty spool of thread.This work as sundial.

Making the Sundial:

1. Using the pencil, poke a hole on the side of the paper / Styrofoam cup pproximately 2 inches below its top (rim).
2. Place the pebbles in the cup so to give it some weight and hold it upright.3. Cover the cup with the plastic lid.
4. Put the straw through the hole on the side of the cup and its lid while letting about half an inch of the straw stick out from the side.
4. Secure the straw to the cup by taping it down on the side.

3. How do you make a pinhole camera?

Ans: Take two rectangular boxes that fit into one another without leaving any gap.
Cut open one side of each box.

Make a small hole in the larger box at the centre of the closed end opposite the side that has been cut open.

Cut a square of side five centimetres in the smaller box in the closed end opposite the side that has been cut open. Cover this square with tracing paper.
Finally, slide the smaller box into the larger box, ensuring that the pinhole and the tracing paper are in line with one another, but at the opposite ends.

Slide the smaller box to adjust the focus so that you can capture the image of any object you want.

Look through the open face of the smaller box. you can see the image of the object and inverted on the screen.

 4. Explain with the help of an activity that light travels in a straight line.

Ans: Place a candle at one corner of the room
Now look through the pipe, you can see the candle
Now bend the pipe and look. you cannot  see the candle
This shows that light travel in straight line called rectilinear propagation of light

5. What is meant by reflection of light ?

Ans: When light fall on smooth or rough surface return back after hitting these surface this phenomenon is called reflection of light

6. What types of image form in pinhole camera?

Ans: Inverted (upside-down)

7. Why is the image formed by a pinhole camera upside down?

Ans: It is because there is no refracting or reflecting optical element to change the path of the rays of light.

8. What happens if we place an opaque object in coloured light?

The colour of light will not affect the shadow, because shadow is the dark patch formed when an object obstructs the path of light

9. On a sunny day, does a bird or an aeroplane flying high in the sky cast its shadow on the ground? Under what circumstances can we see their shadow on the ground?

Ans: when the bird is flying very low close to the ground.

10. You are given a transparent glass sheet. Suggest any two ways to make it translucent without breaking it

Ans:
 (i) By applying oil, grease, butter on it or pasting a butter paper on it.
(ii) Grinding (rubbing) the surface of the glass by any abrasive material.

11. Suggest a situation where we obtain more than one shadow of an object at a time.

Ans: We can obtain more than one shadow of an object if light from more than one source falls on it. [For example during a match being played in a stadium, multiple shadows of players are seen].

12. Three identical towels of red, blue and green colour are hanging on a clothes line in the sun. What would be the colour of shadows of these towels?

Ans: The colour of shadows of all three towels will be the same

13. Using a pinhole camera a student observes the image of two of his friends, standing in sunlight, wearing yellow and red shirt respectively. What will be the colours of the shirts in the image?

Ans: The colours of the image of the shirts will be the same as the colour of the shirt.

14. A football match is being played at night in a stadium with flood lights ON. You can see the shadow of a football kept at the ground but cannot see its shadow when it is kicked high in the air. Explain.

Ans: We can see the shadow of football lying on the ground because the ground acts as a screen for it. However, when the football is kicked high, the ground, which is acting as a screen is away from the football, hence no shadow of the football will be formed on the ground

15. . A student had a ball, a screen and a torch in working condition. He tried to form a shadow of the ball on the screen by placing them at different positions. Sometimes the shadow was not obtained. Explain.

Ans: Possible reasons  (i) The screen away from the ball.
(ii) The beam of light from the torch is falling parallel to the screen on the ball.
(iii) The torch is kept away from the ball.


Lesson 11: Light, Shadows And Reflections.

Solution for Questions in brief                                          View/Download
Hots questions with solution by Physics adda                   View/Download
Quest Time solved question by CBSE ADDA                 View/Download
6th Chapter Light CBSE Test paper-1                            View/Download 
6th Chapter Light CBSE Test paper-2                            View/Download

Comments

CBSE ADDA :By Jsunil Sir : Your Ultimate Destination for CBSE Exam Preparation and Academic Insights

Class 10 Chapter 02 Acid Bases and Salts NCERT Activity Explanation

NCERT Activity Chapter 02 Acid Bases and Salt Class 10 Chemistry Activity 2.1 Indicator Acid Base Red litmus No Change Blue Blue Litmus Red No change Phenolphthalein Colourless Pink Methyl Orange Pink   Yellow Indictors are substance which change colour in acidic or basic media. Activity 2.2 There are some substances whose odour changes in in acidic or basic media. These are called olfactory indicators. Like onion vanilla, onion and clove. These changes smell in basic solution. Activity 2.3 Take about 5 mL of dilute sulphuric acid in a test tube and add few pieces of zinc granules to it. => You will observe bubbles of hydrogen gas on the surface of zinc granules. Zn + H2SO4 --> ZnSO4 + H2 => Pass the Hydrogen gas through the soap solution. Bubbles formed in the soap solution as Hydrogen gas it does not get dissolved in it

Living science ratna sagar class 6 solutions

Ratna sagar living science 6 answers by jsunil. Class6 Living science solution Term-1 Living Science Solution chapter-1 Source of food Download File Living Science Solution chapter-2 Component of food Download File Living Science Solution chapter-3 Fibre to fabric Download File Living Science Sol ch-4 Sorting of material into group Download File Living Science Soln ch-5 Separation of substance Download File Living Science Solution chapter-6 Change around Us Download File Living Science Solution ch-7 Living and Non Living Download File Living Science Solution ch-8 Getting to Know Plants Download File Living Science Sol ch-9 The Body and Its movements Download File Visit given link for full answer Class6 Living science solution Term-II

Class 10 Metal and Non MetalsChapter 03 NCERT Activity Solutions

X Class 10 NCERT Activity Explanation Class 10 Metals and Non Metals Activity 3.1 Page No. 37 Take samples of iron, copper, aluminium and magnesium. Note the appearance of each sample. They have a shining surface. Clean the surface of each sample by rubbing them with sand paper and note their appearance again. They become more shiny. => Freshly cut Metal have shiny surface Activity 3.2 Page No. 37 Take small pieces of iron, copper, aluminium, and magnesium. Try to cut these metals with a sharp knife and note your observations. They are very hard to cut. Hold a piece of sodium metal with a pair of tongs and try to cut it with a knife. Sodium can be cut easily with knife. Hence K and Na are soft metal cut with knife Activity 3.3 Page No. 38 Take pieces of iron, zinc, lead and copper try to strike it four or five times with a hammer. These metals are beaten into thin sheet on hammering. This property of metal is called malleability and metals are called malleable. Activity 3.4 Page

CBSE I NCERT 10th Numerical Problem solved Reflection and reflection of light

Q. 1. A concave mirror of focal length 20cm is placed 50 cm from a wall. How far from the wall an object be placed to form its real image on the wall?  Solution: V= -50 cm F= -20cm From mirror formula 1/u = 1/f – 1/v = -1/20+ 1/50 = - 3/100  U = - 33.3 cm Therefore, the distance of the object from the wall x =  50 – u X = 50 – 33.3 = 16.7 cm. Q.2. An object is placed at a distance of 40cm from a concave mirror of focal length 15cm. If the object is displaced through a distance of 20 cm towards the mirror, By how much distance is the image displaced? Answer: Here f = - 15 cm, u = - 40 cm Now 1/f = 1/u + 1/v Then 1/v = 1/f – 1/u Or V= uf/u-f =( - 40 x -15)/25 = -24 cm Then object is displaced towards the mirror let u1 be the distance object from the Mirror in its new position. Then u1 = -(40-20) = -20cm If the image is formed at a distance u1 from the mirror then v1 = u1f/u1-f = -20X-15/-20+15 = -60 cm. = - 20 x-15/-20+15 = -60 cm. Therefor

Electricity numerical for class 10 CBSE Trend Setter 50 Problems

1. The current passing through a room heater has been halved. What will happen to the heat produced by it? 2. An electric iron of resistance 20 ohm draws a current of 5 amperes. Calculate the heat produced in 30 seconds. 3. An electric heater of resistance 8 ohm takes a current of 15 A from the mains supply line. Calculate the rate at which heat is developed in the heater. 4. A resistance of 40 ohms and one of 60 ohms are arranged in series across 220 volt supply. Find the heat in joules produced by this combination in half a minute. 5. A resistance of 25 ohm is connected to a 12 V battery. Calculate the heat energy in joules generated per minute. 6. 100 joules of heat is produced per second in a 4 ohm resistor. What is the potential difference across the resistor? 7. An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at minimum heating’ it consumes a power of 360 W but at ‘maximum heating’ it takes a power of 840 W. Ca