Write Faraday's laws of electromagnetic induction. [2 + 1]
Mention one advantage of using a LED lamp over an incandescent lamp.
Faraday's law of electromagnetic induction:
LED lamps are more energy-efficient as they consume significantly less power and last longer compared to incandescent lamps.
Question ID: 405
Uploaded on: September 26, 2024
There are 92 protons and 143 neutrons in the nucleus of a radioactive atom. If an α-particle is emitted from that atom how many protons and neutrons will be present in the nucleus of the new atom formed? What type of nuclear reaction is the source of energy of stars? [2 + 1]
After the emission of an α-particle:
The new atom will have 90 protons and 141 neutrons.
The energy of stars is primarily produced by nuclear fusion reactions.
Question ID: 406
Uploaded on: September 26, 2024
Write the contribution of Mendeleef in the creation of the 'periodic table'. [3] OR What is meant by the atomic radius of an atom? Arrange the first three elements C, Si and Ge of group 14 of long periodic table in the order of their increasing atomic radii. [2 + 1]
Mendeleev's contributions to the creation of the periodic table include:
OR
The atomic radius of an atom is the distance from the center of the nucleus to the outermost shell of electrons. It represents the size of the atom.
For group 14 elements (C, Si, Ge):
C < Si < Ge
Question ID: 407
Uploaded on: September 26, 2024
Mention two classes of electrolytes. How can they be differentiated?
Two Classes of Electrolytes:
Differentiation:
Question ID: 408
Uploaded on: September 26, 2024
Write the balanced chemical equation for the reaction that occurs in the Haber process for the industrial manufacture of ammonia. Write the conditions of the process.
Balanced Chemical Equation for the Haber Process:
N2 (g) + 3H2 (g) ⇌ 2NH3 (g)
Conditions of the Process:
Question ID: 409
Uploaded on: September 26, 2024
A hydrocarbon in the substitution reaction with chlorine in diffused sunlight forms methyl chloride in the first step. What is the hydrocarbon? Write balanced chemical equation for the first step of the reaction. Mention one use of the hydrocarbon. [1 + 1 +1] OR What is the industrial source of LPG?
Write one use of each of acetic acid and poly (tetrafluoroethylene). [1 + 2]
The hydrocarbon is methane (CH4).
Balanced Chemical Equation for the First Step:
CH4+ Cl2 {\overset{\text{diffused sunlight}}{\longrightarrow}} CH3 + HCl
In this reaction, methane reacts with chlorine to form methyl chloride (CH3Cl) and hydrogen chloride (HCl).
Use of Methane:
Methane is widely used as a fuel in domestic and industrial applications due to its high energy content.
OR
The primary industrial sources of LPG (Liquefied Petroleum Gas) are natural gas processing and crude oil refining.
Uses:
Question ID: 410
Uploaded on: September 26, 2024
The amount of which greenhouse gas in the atmosphere increases by the burning of fossil fuel? [For External Candidates]
Carbon dioxide.
Question ID: 411
Uploaded on: September 26, 2024
What is the product of the pressure and volume of 32 g of O2 gas at STP? (0 = 16) [For External Candidates]
PV = nRT
= 1 × 0.082 × 273
= 22.4 atm L.
Question ID: 412
Uploaded on: September 26, 2024
What is DC? [For External Candidates]
DC (Direct Current) is a type of electric current that flows in a single, constant direction. In a DC circuit, the electric charge (current) does not change direction.
Question ID: 413
Uploaded on: September 26, 2024
By the emission of which radioactive ray from the atom of a radioactive element, no new atom is created? [For External Candidates]
γ-rays.
Question ID: 414
Uploaded on: September 26, 2024
Draw the structural formula of a saturated hydrocarbon containing two carbon atoms. [For External Candidates]
The structural formula of ethane:
Question ID: 415
Uploaded on: September 26, 2024
What is the importance of insulators in household wiring? [For External Candidates]
Importance of Insulators in Household Wiring:
Question ID: 416
Uploaded on: September 26, 2024