Convex mirrors are used as rear-view mirrors in vehicles because they always form a virtual, erect, and diminished image, providing a wider field of view. Torches and search-lights use concave mirrors (to produce parallel beams), and shaving mirrors use concave mirrors (to produce an enlarged image).
Q2mcq1 mark
The sun is visible to us about two minutes before the actual sunrise and about two minutes even after the actual sunset because of atmospheric
a.
refraction of light
Correct Answer
b.
reflection of light
c.
scattering of light
d.
dispersion of light
Step-by-Step AI Explanation
Verified Method
The sun is visible two minutes before actual sunrise and two minutes after actual sunset due to atmospheric refraction. As sunlight enters the Earth's atmosphere, it bends due to varying densities of air layers, causing the sun to appear higher than its actual position.
Q3mcq1 mark
A current carrying rod is placed between the poles of a horse-shoe magnet. For the maximum displacement of the rod the angle between the direction of electric current and the direction of magnetic field must be
a.
0°
b.
45°
c.
90°
Correct Answer
d.
180°
Step-by-Step AI Explanation
Verified Method
The force on a current-carrying conductor in a magnetic field is given by $F = I L B \sin(\theta)$. The force is maximum when $\sin(\theta)$ is maximum, which occurs when $\theta = 90^\circ$.
Q4short answer1 mark
Draw a symbol diagram of a resistor used in an electric circuit.
Step-by-Step AI Explanation
Verified Method
The symbol for a resistor is represented by a zig-zag line: $--/\/\/\/\--$
Q5short answer1 mark
“Two magnetic field lines do not intersect each other.” Justify.
Step-by-Step AI Explanation
Verified Method
If two magnetic field lines were to intersect, there would be two different directions for the magnetic field at the point of intersection. This is impossible as a compass needle can only point in one direction at any given point.
Q6short answer1 mark
Observe the circuit diagram given below. Mention the direction of magnetic field that forms around the point P and around the point Q.
Step-by-Step AI Explanation
Verified Method
Using the Right-Hand Thumb Rule, the direction of the magnetic field lines around a current-carrying straight conductor forms concentric circles. At point P (assuming it is on one side of the wire), the direction is tangential to the circle, specifically pointing into the page, and at point Q (on the opposite side), it points out of the page.
Q7short answer2 marks
Explain Newton’s experiment that shows the recombination of spectrum of white light.
Step-by-Step AI Explanation
Verified Method
Isaac Newton placed a second identical glass prism in an inverted position with respect to the first prism. The first prism disperses white light into its constituent colors. When these colors fall on the second inverted prism, it recombines them to produce a beam of white light on the other side. This proves that white light is composed of seven colors.
Q8short answer2 marks
Write any two differences between near-sighted (Myopic) and far-sighted (Hypermetropic) eyes.
Step-by-Step AI Explanation
Verified Method
1. In Myopia (near-sightedness), the person can see nearby objects clearly but distant objects are blurred; in Hypermetropia (far-sightedness), the person can see distant objects clearly but nearby objects are blurred.
2. Myopia is corrected using a concave lens, whereas Hypermetropia is corrected using a convex lens.
Q9long answer3 marks
Draw the ray diagram of image formed when an object is kept at $2F_1$ of the convex lens. With the help of the ray diagram write the position and nature of the image. ($F_1$ : Principal focus of the lens)
Step-by-Step AI Explanation
Verified Method
Ray Diagram: Draw a convex lens with optical center O. Place object AB at $2F_1$. Draw a ray parallel to principal axis which passes through $F_2$ after refraction. Draw a second ray through O which emerges undeviated. The rays intersect at $2F_2$.
Position of image: The image is formed at $2F_2$ on the other side of the lens.
Nature of image: Real, inverted, and of the same size as the object.
Q10long answer3 marks
a) State Ohm’s law.
b) Write the factors on which the resistance of a conductor depends.
Step-by-Step AI Explanation
Verified Method
a) Ohm's Law states that the electric current flowing through a metallic conductor is directly proportional to the potential difference across its ends, provided its temperature remains constant. Mathematically: $V \propto I$ or $V = IR$.
b) The resistance of a conductor depends on: 1) Nature of the material, 2) Length of the conductor ($R \propto l$), 3) Area of cross-section ($R \propto \frac{1}{A}$), and 4) Temperature of the conductor.
🎉 10 Free Sample Solutions Completed
Unlock All 48 Questions & Solutions
Sign up free in seconds to unlock step-by-step AI answers for the remaining 38 questions.
a) What factor helps for determining the relative strength of a magnetic field?
b) What is solenoid? How is an electromagnet prepared by using it?
OR
In domestic electric circuits,
a) What is the function of earth wire?
b) What precautions should be taken to avoid overloading?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) How is an ammeter and a voltmeter connected to an electric circuit? Mention their function.
b) “In domestic electric circuit, the electrical appliances are generally connected in parallel.” Give reasons.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
The radius of curvature of a spherical mirror is 36 cm. Find its focal length. A candle of 5 cm length is placed at a distance of 27 cm in front of a convex mirror of the same focal length. Mention the position and nature of the image and also find the size of the image formed.
OR
The focal length of a spherical mirror is 10 cm. Find its radius of curvature. An object of 4 cm size is placed at 20 cm in front of a concave mirror of the same focal length. At what distance from the mirror should a screen be placed in order to obtain a sharp image of the object? Mention the nature of the image formed and also find the size of the image.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
The radius of curvature of a spherical mirror is 36 cm. Find its focal length. A candle of 5 cm length is placed at a distance of 27 cm in front of a convex mirror of the same focal length. Mention the position and nature of the image and also find the size of the image formed.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Complete the following oxidation reaction and name the functional group that is found in the product : $CH_{3}CH_{2}OH \xrightarrow{Alkaline \ KMnO_{4} \ or \ acidified \ K_{2}Cr_{2}O_{7} + Heat}$
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
The focal length of a spherical mirror is 10 cm. Find its radius of curvature. An object of 4 cm size is placed at 20 cm in front of a concave mirror of the same focal length. At what distance from the mirror should a screen be placed in order to obtain a sharp image of the object ? Mention the nature of the image formed and also find the size of the image.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Draw the diagram of the arrangement of apparatus used to show the electrolytic refining of copper. Label the following parts : i) Cathode ii) Impurities.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Write the chemical equations for the following reactions. i) Quicklime is reacted with water ii) Zinc pieces are added to copper sulphate solution iii) Sodium chloride solution is added to silver nitrate solution.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) $NaOH, Ca(OH)_{2}, H_{2}$ and $Cl_{2}$ materials are given to you. By using which of these materials, you can prepare bleaching powder ? Write the chemical name and one use of the bleaching powder. b) i) How do you identify a solution as basic solution by using blue litmus paper ? ii) Under what condition does a farmer treat the soil of his field with slaked lime ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
a) Write any two differences between saturated and unsaturated carbon compounds. b) What are structural isomers ? Write the structural isomers of butane. c) Write the electron dot structure of methane molecule.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
The events that occur during photosynthesis are given below. Write these events in correct order.
i) Splitting of water molecules into hydrogen and oxygen
ii) Absorption of light energy by chlorophyll
iii) Conversion of carbon dioxide to carbohydrates
iv) Conversion of light energy to chemical energy.
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
How do auxins promote the growth of tendrils of climbing plants around a support ?
OR
How does our body respond when adrenaline is secreted into the blood ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Construct a food chain using the organisms ; snake, frog, grass and grasshopper. Which organism has more accumulation of harmful chemicals in this food chain ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Justify the following statements :
a) Sexual type of reproduction leads to more variations.
b) In woman’s uterus the role of placenta is significant for the development of foetus.
OR
a) How does menstruation occur in women ?
b) In male reproductive system the testes are located outside the abdominal cavity in scrotum. Why ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
Round green colour ( RRyy ) seeds producing pea plant is crossed with wrinkled yellow colour seeds ( rrYY ) producing pea plant. Show the result of $F_2$ generation with the help of a checker board and write the ratio of varieties of plants.
OR
a) Explain the sex determination of a child in human beings.
b) How can the traits of organisms be decided as either dominant or recessive ?
Correct Answer & Step-by-Step Solution Locked
Sign in free to reveal the correct answer and AI explanation for this question.
