Match List I with list II and select the correct answer using the codes given below the lists:
[question] Question. Match List I with list II and select the correct answer using the codes given below the lists: [solution] Solution: [solution]...
Read More →An object of mass 1 kg travelling in a straight line with a velocity of 10 ms–1 collides with,
[question] Question. An object of mass 1 kg travelling in a straight line with a velocity of 10 ms–1 collides with, and sticks to a stationary wooden block of mass 5 kg. Then they both move off together in the same straight line. Calculate the total momentum just before the impact and just after the impact. Also, calculate the velocity of the combined object. [/question] [solution] Solution: For object : $\mathrm{m}_{1}=1 \mathrm{~kg} ; \mathrm{u}_{1}=10 \mathrm{~ms}^{-1}$ For wooden block: $\ma...
Read More →The magnification produced by a plane mirror
[question] Question. The magnification produced by a plane mirror is $+1$. What does this mean ? [/question] [solution] solution: Magnification for a plane mirror is $+1$. The positive sign means the image is virtual and erect. The numerical value (magnitude) '1' means that the size of the image is exactly equal to the size of the object. [/solution]...
Read More →An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm.
[question] Question. An object is placed at a distance of 10 cm from a convex mirror of focal length 15 cm. Find the position and nature of the image. [/question] [solution] solution: Given, object distance, $\mathrm{u}=-10 \mathrm{~cm}$; focal length, $f=+15 \mathrm{~cm}$; image distance, $\mathrm{v}=? ;$ magnification, $\mathrm{m}=?$ Mirror formula, $\frac{1}{v}+\frac{1}{u}=\frac{1}{f} \quad$ or $\quad \frac{1}{v}+\frac{1}{(-10)}=\frac{1}{(+15)}$ or $\frac{1}{v}=\frac{1}{10}+\frac{1}{15}=\frac...
Read More →Match List I (organisations and struggles) with List II and select the correct answer using the codes given below the lists:
[question] Question. Match List I (organisations and struggles) with List II and select the correct answer using the codes given below the lists: [/question] [solution] Solution: [/solution]...
Read More →A bullet of mass 10 g travelling horizontally with a velocity
[question] Question. A bullet of mass 10 g travelling horizontally with a velocity of 150 ms–1 strikes a stationary wooden block and comes to rest in 0.03 s. Calculate the distance of penetration of the bullet into the block. Also calculate the magnitude of the force exerted by the wooden block on the bullet. [/question] [solution] Solution: Mass of bullet, $\mathrm{m}=10 \mathrm{~g}=0.01 \mathrm{~kg} ;$ initial velocity of bullet, $\mathrm{u}=150 mathrm{~ms}^{-1} ;$ final velocity of bullet, $\...
Read More →An object 5 cm in length is held 25 cm away
[question] Question. An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed. [/question] [solution] solution: Given, $\mathrm{h}_{1}=+5 \mathrm{~cm} ; \mathrm{u}=-25 \mathrm{~cm}$ $\mathrm{f}=+10 \mathrm{~cm}$ By lens equation, $\frac{1}{v}-\frac{1}{u}=\frac{1}{f}$ or $\frac{1}{v}-\frac{1}{(-25)}=\frac{1}{+10}$ or $\frac{1}{v}+\frac{1}{25}=\frac{1}{+10}$ or $\frac{1}{v}=\frac{1}...
Read More →Which among the following is the special feature that distinguishes a pressure group from a political party?
[question] Question. Which among the following is the special feature that distinguishes a pressure group from a political party? (a) Parties take political stances, while pressure groups do not bother about political issues. (b) Pressure groups are confined to a few people, while parties involve larger number of people. (c) Pressure groups do not seek to get into power, while political parties do. (d) Pressure groups do not seek to mobilise people, while parties do. [/question] [solution] Solut...
Read More →Organisations that undertake activities to promote the interests of specific social sections such as workers,
[question] Question. Organisations that undertake activities to promote the interests of specific social sections such as workers, employees, teachers, and lawyers are called _____________ groups. [/question] [solution] Solution: Organisations that undertake activities to promote the interests of specific social sections such as workers, employees, teachers, and lawyers are called sectional interest groups. [/solution]...
Read More →A hockey ball of mass 200 g travelling at 10 ms–1 is struck
[question] Question. A hockey ball of mass 200 g travelling at 10 ms–1 is struck by a hockey stick so as to return it along its original path with a velocity of 5 ms–1. Calculate the change of momentum which occurred in the motion of the hockey ball by the force applied by the hockey stick. [/question] [solution] Solution: Mass of ball, $\mathrm{m}=200 \mathrm{~g}=0.2 \mathrm{~kg} ;$ initial velocity of ball, $\mathrm{u}_{1}=10 \mathrm{~ms}^{-1} ;$ final velocity of ball, $\mathrm{u}_{2}=-5 \mat...
Read More →One-half of a convex lens is covered with a black paper.
[question] Question. One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations. [/question] [solution] solution: The convex lens will form complete image of an object, even if its one half is covered with black paper. Only the brightness of the image will reduce, in this case it will be half of the brightness of original image. It can be understood by the following two cases: (a) Le...
Read More →What is the difference between a pressure group and a political party?
[question] Question. What is the difference between a pressure group and a political party? [/question] [solution] Solution: The major difference between pressure groups and political parties is that unlike political parties, pressure groups do not aim to directly control or share political power. [/solution]...
Read More →What is a pressure group? Give a few examples.
[question] Question. What is a pressure group? Give a few examples. [/question] [solution] Solution: A pressure group is an organisation which attempts to influence government policies through protests and demonstrations. Pressure groups are formed when people with similar opinions get together for similar objectives. Examples of pressure groups are FEDECOR and BAMCEF. [/solution]...
Read More →According to the third law of motion when we push on an object,
[question] Question. According to the third law of motion when we push on an object, the object pushes back on us with an equal and opposite force. If the object is a massive truck parked along the roadside, it will probably not move. A student justifies this by answering that the two opposite and equal forces cancel each other. Comment on this logic and explain why the truck does not move. [question] [solution] Solution: When we push a massive truck parked along the roadside, it does not move. ...
Read More →Two objects, each of mass 1.5 kg,
[question] Question. Two objects, each of mass 1.5 kg, are moving in the same straight line but in opposite directions. The velocity of each object is 2.5 ms–1 before the collision during which they stick together. What will be the velocity of the combined object after collision ? [/question] [solution] Solution: Let the objects be $\mathrm{A}$ and $\mathrm{B}$ moving from opposite directions in the same straight line. $\therefore$ Initial momentum of $\mathrm{A}=\mathrm{m} \times \mathrm{v}$ $=...
Read More →Explain how the activities of pressure groups are useful in the functioning of a democratic government.
[question] Question. Explain how the activities of pressure groups are useful in the functioning of a democratic government. [/question] [solution] Solution: Pressure groups are important in the functioning of a democratic government as they provide an opportunity for marginalised people to voice their opinions. In some cases, the government’s opinion might be biased by a small group of rich and powerful people. It is here that pressure groups step in and force the government to make policies wh...
Read More →Name the type of mirror used in the following situations
[question] Question. Name the type of mirror used in the following situations (a) Headlights of a car. (b) Side/rear-view mirror of a vehicle. (c) Solar furnace. Support your answer with reason. [/question] [solution] solution: (a) Concave mirror. Concave mirror is used in the headlights of a vehicle because it produces powerful and almost parallel beam of light when the light source is placed at its principal focus. A bulb placed at the focus of a concave mirror produces a strong, almost parall...
Read More →Describe the forms of relationship between pressure groups and political parties?
[question] Question. Describe the forms of relationship between pressure groups and political parties? [/question] [solution] Solution: The relationship between political parties and pressure groups can take different forms. (i) Pressure groups are often formed and led by politicians and political parties. Most trade unions and students’ organisations in India are either established by, or affiliated to one or the other major political party. (ii) Political parties sometimes grow out of movement...
Read More →Describe the forms of relationship between pressure groups and political parties?
[question] Question. Describe the forms of relationship between pressure groups and political parties? [question] [solution] Solution: The relationship between political parties and pressure groups can take different forms. (i) Pressure groups are often formed and led by politicians and political parties. Most trade unions and students’ organisations in India are either established by, or affiliated to one or the other major political party. (ii) Political parties sometimes grow out of movements...
Read More →In what ways do pressure groups and movements exert influence on politics?
[question] Question. In what ways do pressure groups and movements exert influence on politics? [/question] [solution] Solution: Pressure groups and movements exert influence on politics in a variety of ways. (i) They try to gain public support and sympathy for their cause by carrying out information campaigns, organising meetings, filing petitions, etc. (ii) By organising strikes and disruptions, they seek to make the government take note of their demands. (iii) They also influence decision-mak...
Read More →Match List I with List II and select the correct answer using the codes given below the Lists:
[question] Question. Match List I with List II and select the correct answer using the codes given below the Lists: [/question] [solution] Solution: [/solution]...
Read More →Which of the following lenses would you prefer
[question] Question. Which of the following lenses would you prefer to use while reading small letters found in a dictionary? (a) A convex lens of focal length 50 cm (b) A concave lens of focal length 50 cm (c) A convex lens of focal length 5 cm (d) A concave lens of focal length 5 cm [/question] [solution] solution: Option (c) is correct. For reading small letters in a dictionary, a convex lens of small focal length is used as it is kept quite close to the page of the dictionary. [/solution]...
Read More →Using a horizontal force of 200 N,
[question] Question. Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet ? [question] [solution] Solution: In order to move the cabinet with constant velocity, the net force acting on it should be zero, such that the forces are balanced. This is possible only if the frictional force is 200 N and acts in the direction opposite to the direction of motion of the cabinet....
Read More →Social divisions based on
[question] Question. Social divisions based on ______________ are peculiar to India. [/question] [solution] Solution: Social divisions based on caste are peculiar to India. [/solution]...
Read More →What is the momentum of an object of mass m, moving with a velocity v ?
[question] Question. What is the momentum of an object of mass m, moving with a velocity v ? (a) (mv)2 (b) mv2 (c) 1/2mv2 (d) mv [question] [solution] Solution: Correct answer is option (d). [solution]...
Read More →