All India JEE Group

Which of the following group 14 elements can decompose steam to form dioxide and liberate H2?
  • a)
    Sn
  • b)
    Pb
  • c)
    C
  • d)
    Ge
Correct answer is option 'A'. Can you explain this answer?

Ashutosh Sengupta answered  •  39 minutes ago

Decomposition of steam by Group 14 element Sn:

- Group 14 elements:
- Group 14 elements include carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb).

- Decomposition of steam:
- When steam (H2O) is decomposed, it forms dioxide (O2) and liberates hydrogen gas (H2).

- Reaction with Sn:
- Sn (tin)
... more

Find the number of bijective functions from set A to itself when A contains 106 elements.
  • a)
    106 
  • b)
    106
  • c)
    106!
  • d)
    2106
Correct answer is option 'D'. Can you explain this answer?

Ashutosh Sengupta answered  •  44 minutes ago




Explanation:




Counting Bijective Functions:

- A bijective function is a function that is both injective (one-to-one) and surjective (onto).
- For a bijective function from a set A to itself, each element in A must be mapped to a unique element in A.
- Since there are 106 elements in set A, each eleme
... more

For any two real numbers θ and ϕ, we define θRϕ , if and only if sec2 θ - tan2ϕ =1. The relation R is
  • a)
    reflexive but not transitive
  • b)
    symmetric but not reflexive
  • c)
    both reflexive and symmetric but not transitive
  • d)
    an equivalence relation
Correct answer is option 'D'. Can you explain this answer?

Ashutosh Sengupta answered  •  49 minutes ago

Equivalence Relation Explanation:


Equivalence relations have three main properties: reflexivity, symmetry, and transitivity. Let's break down each property in this context:


Reflexivity:
For any real number θ, we have sec2θ - tan2θ = 1. This means that θ R θ is true because substituting the same number on bot
... more

The atmospheric lapse rate
For small volumes of gas, according to kinetic theory of gases, all parts of the gas are at the same temperature. But for huge volumes of gas like atmosphere, assumption of a uniform temperature throughout the gas is not valid. Different parts of the atmosphere are at different temperatures. Apart from the surface of the earth, variations also occur in temperature at different heights in the atmosphere.
The decrease in temperature with height called the atmospheric lapse rate is similar at various locations across the surface of the Earth. By analyzing the data collected at various locations, it is found that average global lapse rate is – 6.7 °C/Km.
The linear decrease with temperature only occurs in the lower part of the atmosphere called the troposphere. This is the part of the atmosphere in which weather occurs and our planes fly. Above the troposphere is the stratosphere, with an imaginary boundary separating the two layers. In the stratosphere, temperature tends to be relatively constant.
Absorption of sunlight at the Earth’s surface warms the troposphere from below, so vertical convection currents are continually mixing in the air. As a parcel of air rises, its pressure drops and it expands. The parcel does work on its surrounding, so that its internal energy and therefore, its temperature drops. Assume that the vertical mixing is so rapid as to be adiabatic and the quantity TP(1 – λ)/λ has a uniform value through the layers of troposphere.
(M is molecular mass of the air, R is universal gas constant, g is gravitational acc., P and T are pressure and temperature respectively at the point under consideration and y is height.)
Q.    The value of theoretical lapse rate on the earth is (use g = 9.8 m/s2 ;  R = 8.3 J/mol-k and M = 29 g/mol)
... more

Sahil Sengupta answered  •  7 hours ago

Calculation of Theoretical Lapse Rate

The theoretical lapse rate can be calculated using the formula:

\[ \Gamma = \frac{g}{C_p} \]

Where:
- \( \Gamma \) = Lapse rate
- g = Gravitational acceleration (9.8 m/s\(^2\))
- \( C_p \) = Specific heat at constant pressure

Calculating \( C_p \)

The specific heat at con
... more

There are two thin spheres A and B of the same material and same thickness. They emit like black bodies. Radius of A is double that of B. A and B have same temperature T. When  A and B are kept in a room of temperature T0 (< T), the ratio of their rates of cooling (rate of fall of temperature) is: [ assume negligible heat exchange between A and B ]
  • a)
    2 : 1
  • b)
    1 : 1
  • c)
    4 : 1
  • d)
    8 : 1
Correct answer is option 'B'. Can you explain this answer?

Pallavi Ahuja answered  •  7 hours ago

Explanation:

Rate of cooling depends on surface area:
- The rate of cooling of an object is directly proportional to its surface area.
- In this case, sphere A has a radius twice that of sphere B, which means the surface area of sphere A is four times that of sphere B.

Ratio of rates of cooling:
- Since the rates of cooling are direct
... more

A man standing on the top of a tower 60m height throws a ball in the verticaly upward direction with a velocity 20m/s.the total distance travelled by the ball in moving upwards and returning to the thrower is 1. 10m 2. 20... more

Upasana Choudhury answered  •  9 hours ago


Understanding the Problem:
The problem involves a man standing on a tower who throws a ball vertically upward with a velocity of 20m/s. We need to calculate the total distance traveled by the ball in moving upwards and returning to the thrower.

Key Concepts:
- The ball's initial velocity is 20m/s upwards.
- The acceleration due to gravity is -9.8
... more

An open glass tube is immersed in mercury in such a way that a length of 8 cm extends above the mercury level. The open end of the tube is then closed and sealed and the tube is raised vertically up by additional 46 cm. What will be the length of the air column above mercury in the tube now? (Atmospheric pressure = 76 cm of Hg)
  • a)
    16
  • b)
    22
  • c)
    38
  • d)
    6
Correct answer is option 'A'. Can you explain this answer?

Arshiya Rane answered  •  14 hours ago
Explanation:

Given data:
- Length of the air column above mercury initially = 8 cm
- Additional height raised = 46 cm
- Atmospheric pressure = 76 cm of Hg

Calculation:
- Initially, the pressure inside the tube is equal to the atmospheric pressure. So, the pressure of mercury column = Pressure of air column
- Pressure = hρg, where
... more

The freezing point of a diluted milk sample is found to be –0.2°C, while it should have been –0.5°C for pure milk. How much water has been added to pure milk to make the diluted sample?
  • a)
    2 cups of water to 3 cups of pure milk
  • b)
    1 cup of water to 3 cups of pure milk
  • c)
    3 cups of water to 2 cups of pure milk
  • d)
    1 cup of water to 2 cups of pure milk
Correct answer is option 'C'. Can you explain this answer?

Dipika Patel answered  •  15 hours ago
How much water has been added to pure milk to make the diluted sample?

Explanation:

- Given:
- Freezing point of diluted milk sample = -0.2°C
- Freezing point of pure milk = -0.5°C

- Formula:
- The depression in freezing point (∆Tf) is given by the formula: ∆Tf = Kf * m
- Where Kf is the cryoscopic constant for wate
... more

Consider the ground state configuration of Cr atom (Z = 24). The total numbers of electrons with azimuthal quantum numbers l = 1 and l = 2, respectively, are
  • a)
    12 and 4
  • b)
    12 and 5
  • c)
    16 and 4
  • d)
    16 and 5
Correct answer is option 'B'. Can you explain this answer?

Harshad Unni answered  •  18 hours ago


Explanation:

Ground state configuration of Cr atom (Z = 24):
- The ground state electron configuration of chromium (Z = 24) is [Ar] 3d^5 4s^1.

Number of electrons with azimuthal quantum number l = 1:
- In the ground state configuration of chromium, the 4s orbital contains 1 electron with l = 0.
- The azimuthal quantum number l =
... more

An object 20 cm high produces using a lens a real image of 80cm.When an object is shifted by 5 cm a real image 40 cm high is produced.The power of the lens is
  • a)
    0.2 Dipotre
  • b)
    2 Dipotre
  • c)
    2.5 Dipotre
  • d)
    5 Dipotre
Correct answer is option 'D'. Can you explain this answer?

Anand Sen answered  •  19 hours ago

Given Data:
- Object height (h1) = 20 cm
- Image height (h2) = 80 cm
- Object shift (Δx) = 5 cm
- Image height with shift (h3) = 40 cm

Calculation:
- Using the lens formula, 1/f = 1/v - 1/u, where f is the focal length, v is the image distance, and u is the object distance.
- For the original position of the object:
- 1/f = 1/80
... more

How to make a lapyop?

Palak Nair answered  •  21 hours ago


Materials Needed:
- Motherboard
- Processor
- RAM
- Hard Drive
- Keyboard
- Screen
- Battery
- Laptop shell

Steps to Make a Laptop:

1. Assemble the Motherboard:
- Begin by installing the processor onto the motherboard.
- Insert the RAM modules into the designated slots on the motherboard.
... more

A teacher of a class wants to set one question from each of two exercises in a book. If there are 15 and 12 questions in the two exercises respectively, then in how many ways can the two questions be selected?
  • a)
    160
  • b)
    140
  • c)
    180
  • d)
    120
Correct answer is option 'C'. Can you explain this answer?

Nishanth Joshi answered  •  yesterday

Solution:

Combination of Questions:
To select one question from each exercise, we need to find the number of ways the two questions can be selected.

Number of Questions:
Exercise 1: 15 questions
Exercise 2: 12 questions

Number of Ways:
To select one question from each exercise, the number of ways can be calculat
... more

How many five digit numbers can be formed by using the digits 1,2,3,4,5 without repetition of digits?
  • a)
    120
  • b)
    240
  • c)
    150
  • d)
    160
Correct answer is option 'A'. Can you explain this answer?

Nishanth Joshi answered  •  yesterday

Explanation:

Total number of digits:
- Given that we have 5 digits - 1, 2, 3, 4, 5.

Number of choices for the first digit:
- We have 5 choices for the first digit.

Number of choices for the second digit:
- After selecting the first digit, we have 4 remaining choices for the second digit.

Number of choic
... more
- After selecting the first two digits, we have 3 remaining choices for the third digit.

Number of choices for the fourth digit:
- After selecting the first three digits, we have 2 remaining choices for the fourth digit.

Number of choices for the fifth digit:
- After selecting the first four digits, we have 1 remaining choice for the fifth digit.

Total number of five-digit numbers:
- To find the total number of five-digit numbers that can be formed using the given digits without repetition, we multiply the number of choices for each digit: 5 x 4 x 3 x 2 x 1 = 120.

Therefore, the correct answer is option A) 120.

The differential equation whose solution is Ax2 + By2 = 1 where A and B are arbitrary constants is of
  • a)
    second order and second degree
  • b)
    first order and second degree
  • c)
    first order and first degree
  • d)
    second order and first degree
Correct answer is option 'D'. Can you explain this answer?

Nishanth Joshi answered  •  yesterday

Explanation:

Differential Equation Analysis:
- The given equation Ax^2 + By^2 = 1 represents an ellipse in the xy-plane.
- To find the differential equation corresponding to this ellipse, we need to differentiate the given equation with respect to x.

Differentiation:
- Differentiating Ax^2 + By^2 = 1 with respect to x, we get:
2A
... more

An electron and a proton are moving on straight parallel paths with same velocity. They enter a semiinfinite
region of uniform magnetic field perpendicular to the velocity. Which of the following statement(s) is / are true?
  • a)
    They will never come out of the magnetic field region
  • b)
    They will come out travelling along parallel paths.
  • c)
    They will come out at the same time.
  • d)
    They will come out at different times.
Correct answer is option 'B,D'. Can you explain this answer?

Hridoy Shah answered  •  yesterday

Explanation:

Initial Conditions:
- An electron and a proton are moving on straight parallel paths with the same velocity.
- They enter a semi-infinite region of uniform magnetic field perpendicular to their velocity.

Effects of Magnetic Field:
- When a charged particle enters a magnetic field perpendicular to its velocity, it experien
... more

A physical quantity x depends on quantities y and z as follows: x= Ay + BtanCz , where A,B and C are constants . which of the following do not have the same dimensions

Hridoy Shah answered  •  yesterday

Analysis of Dimensions

- Given Equation: x = Ay + BtanCz
- Dimensions of Quantities:
- x has dimensions [x]
- y has dimensions [y]
- z has dimensions [z]
- A, B are constants
- C is dimensionless

Determination of Dimensions

- Dimensions of Ay term:
- Dimensions of Ay = [A][y]
... more

Direction: Read the passage carefully and choose the best answer to each question out of the four alternatives and mark it by blackening the appropriate circle [·].
Like watering a plant, we grow our friendships [and all our relationships) by running them. Friendships need the same attention as other relationships. If they are to continue. These relationships can be delightfully non-judgemental, supportive, understanding and fun.
Sometimes a friendship can  bring out the positive side that you never show in any other relationship. This may be because the pressure of playing a 'role' (daughter, partner or child) is removed.
With a friend you are to be yourself and free to change.
Of course, you are free  to do this in all other relationships as well, but in friendships you get to have lats of rehearsals and discussion about changes as you experience them. It is an unconditional experience where you receive as much as you give.
You can explain yourself to a friend openly without the fear of hurting a family member. How do friendships grow ? The answer is simple. By revealing yourself; being attentive: remembering what is most showing empathy; seeing the world through the eyes of your friend, you will understand the value of friendship. All this means learning to accept a person from a completely different family to your own or perhaps someone from a completely different cultural background. This is the way we learn tolerance. In turn we gain tolerance and acceptance for our own differences.
Q. Through strong friendships, we gain
... more

Prateek Choudhury answered  •  yesterday
Importance of Strong Friendships

Friendships play a crucial role in our lives, providing us with a sense of belonging, support, and understanding. Through strong friendships, we gain more than just acceptance. Let's explore the various benefits below:

Acceptance and Tolerance
- Strong friendships allow us to be ourselves without the fear of judgment. This a
... more

Direction: Read the passage carefully and choose the best answer to each question out of the four alternatives and mark it by blackening the appropriate circle [·].
Like watering a plant, we grow our friendships [and all our relationships) by running them. Friendships need the same attention as other relationships. If they are to continue. These relationships can be delightfully non-judgemental, supportive, understanding and fun.
Sometimes a friendship can  bring out the positive side that you never show in any other relationship. This may be because the pressure of playing a 'role' (daughter, partner or child) is removed.
With a friend you are to be yourself and free to change.
Of course, you are free  to do this in all other relationships as well, but in friendships you get to have lats of rehearsals and discussion about changes as you experience them. It is an unconditional experience where you receive as much as you give.
You can explain yourself to a friend openly without the fear of hurting a family member. How do friendships grow ? The answer is simple. By revealing yourself; being attentive: remembering what is most showing empathy; seeing the world through the eyes of your friend, you will understand the value of friendship. All this means learning to accept a person from a completely different family to your own or perhaps someone from a completely different cultural background. This is the way we learn tolerance. In turn we gain tolerance and acceptance for our own differences.
Q. Friendships and relationships grow when they are
... more

Prateek Choudhury answered  •  yesterday


Friendships and Relationships: Nurturing Growth

Friendships and relationships grow when they are nurtured through various means. Here's an explanation of how nurturing plays a crucial role in the growth of friendships and relationships:

Revealing Yourself
- By revealing your true self to your friend, you are allowing them to see the real you. Th
... more

Find the next term of the series:
319, 320, 347, 472, 815, ?
  • a)
    1322
  • b)
    1265
  • c)
    1148
  • d)
    1544
Correct answer is option 'D'. Can you explain this answer?

Manoj Patel answered  •  yesterday

Observing the Series:
The given series is: 319, 320, 347, 472, 815, ?

Identifying the Pattern:
- Looking at the differences between consecutive terms:
- 320 - 319 = 1
- 347 - 320 = 27
- 472 - 347 = 125
- 815 - 472 = 343

- The differences between consecutive terms are perfect squares: 1^2, 3^3, 5^2, 7^2.

A
... more
To find the next term in the series, we continue the pattern of adding the next perfect square to the last term:
- 815 + 9^2 = 815 + 81 = 896

Therefore, the next term in the series is 896.

Answer:
Therefore, the next term in the series is 896.

The national disaster management authority?

Manoj Patel answered  •  yesterday
National Disaster Management Authority

The National Disaster Management Authority (NDMA) is a governmental body in India responsible for planning, coordinating, and implementing disaster management strategies. It was established in 2005 under the Disaster Management Act of 2005.

Key Functions of NDMA

- **Policy Formulation**: NDMA formulates policies, plans, and gu
... more

?

Athira Das answered  •  yesterday


Introduction:

Shashi Bhuvan Tiwari's book of Physics is a comprehensive resource for students preparing for JEE Main & Advanced exams. It covers a wide range of topics and provides in-depth explanations and practice problems to help students master the concepts.

DPP: Daily Practice Problems:

- The book includes a section called DPP which s
... more
Fetching relevant content for you