JEE Main Daily Practice Questions 12 January 2025

JEE Main Daily Practice Questions 12 January 2025: JEE Main Session 1 2025 will take place from January 22 to 31. Applicants preparing for the exam must focus on practising the JEE Main sample papers. Hence, here are some daily practice questions with answers for JEE Main 12 January  2025, including five questions from each subject: Mathematics, Physics, and Chemistry.

Also Read | NEET Daily Practice Questions 12 January 2025

JEE Main Daily Practice Questions 12 January 2025: Physics

Candidates can check out the JEE Main daily practice questions 12 January 2025 from the Physics section:

Question 1: The activity of a radioactive material is 6.4 × 10–4 curie. Its half life is 5 days. The activity will become 5 × 10–6 curie after

(A) 7 days

(B) 15 days

(C) 25 days

(D) 35 days

Answer (D)

Question 2: For a constant collector-emitter voltage of 8 V, the collector current of a transistor reached the value of 6 mA from 4 mA, whereas base current changed from 20 mA to 25 mA value. If transistor is in active state, small signal current gain (current amplification factor) will be

(A)   240

(B)   400

(C)   0.0025

(D)  200

Answer (B)

Question 3: A parallel plate capacitor with width 4 cm, length 8 cm and separation between the plates of 4 mm is connected to a battery of 20 V. A dielectric slab of dielectric constant 5 having length 1 cm, width 4 cm and thickness 4 mm is inserted between the plates of parallel plate capacitor. The electrostatic energy of this system will be   e0 J. (Where e0 is the permittivity of free space)

(A) 200

(B) 220

(C) 240

(D) 260

Answer (C)

Question 4: A spherical soap bubble of radius 3 cm is formed inside another spherical soap bubble of radius 6 cm. If the internal pressure of the smaller bubble of radius 3 cm in the above system is equal to the internal pressure of the other single soap bubble of radius r cm. The value of r is

(A) 1

(B) 2

(C) 3

(D) 4

Answer (B)

Question 5: A wire of length 30 cm, stretched between rigid supports, has its nth and (n + 1)th harmonics at 400 Hz and 450 Hz, respectively. If tension in the string is 2700 N, it’s linear mass density is ________  kg/m.

(A)  1

(B)  3

(C)  5

(D)  7

Answer (B)

JEE Main Daily Practice Questions 12 January 2025: Chemistry

Candidates can check out the JEE Main daily practice questions 12 January 2025 from the Chemistry section:

Question 1: When a certain amount of solid A is dissolved in 100 g of water at 25°C to make a dilute solution, the vapour pressure of the solution is reduced to one- half of that of pure water. The vapour pressure of pure water is 23.76 mmHg. The number of moles of solute A added is          . (Nearest Integer)

(A) 6

(B) 8

(C) 10

(D) 12

Answer (A)

Question 2: A gas (Molar mass = 280 g mol–1) was burnt in excess O2 in a constant volume calorimeter and during combustion the temperature of the calorimeter increased from 298.0 K to 298.45 K. If the heat capacity of calorimeter is 2.5 kJ K–1 and enthalpy of combustion of gas is 9 kJ mol–1 then amount of gas burnt is     g. (Nearest Integer)

(A) 30

(B) 35

(C) 40

(D) 45

Answer (B)

Question 3: Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is  .

(A) 1

(B) 2

(C) 3

(D) 4

Answer (D)

Question 4: 2.4 g coal is burnt in a bomb calorimeter in excess of oxygen at 298 K and 1 atm pressure. The temperature of the calorimeter rises from 298 K to 300 K. The enthalpy change during the combustion of coal is –x kJ mol–1. The value of x is  _____. (Nearest integer)

(Given : Heat capacity of bomb calorimeter is 20.0 kJ K–1. Assume coal to be pure carbon)

(A) 100

(B)  200

(C)  300

(D) 400

Answer (B)

Question 5: 0.8 g of an organic compound was analysed by Kjeldahl’s method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then  ______  mL of 1 M H2SO4 would have been neutralized by the ammonia evolved during the analysis.

(A)  8

(B) 10

(C) 12

(D) 14

Answer (C)

JEE Main Daily Practice Questions 12 January 2025: Mathematics

Candidates can check out the JEE Main daily practice questions 12 January 2025 from the Maths section:

Problem 1: A seven digit number is formed using digits 3, 3, 4, 4, 4, 5, 5. The probability, that number so formed is divisible by 2, is :

(1) 1/7

(2) 6/7

(3) 4/7

(4) 3/7

Solution (4)

Problem 2:

Let C be the locus of the mirror image of a point on the parabola y2 = 4x with respect to the line y = x. Then the equation of tangent to C at P(2, 1) is :

(1)  x + 2y = 4

(2) 2x + y = 5

(3) x – y = 1

(4) x + 3y = 5

Solution  (3)

Problem 3: Let A(–1, 1), B(3, 4) and C(2, 0) be given three points. A line y = mx, m > 0, intersects lines AC and BC at point P and Q respectively. Let A1 and A2 be the areas of DABC and DPQC respectively, such that A1 = 3A2, then the value of m is equal to :

(1) 0

(2) 1

(3) 2

(4) 3

Solution (2)

Problem 4: If the equation of plane passing through the mirror image of a point (2, 3, 1) with respect to line (x+1)/2 =(y-3)/1= (z+2)/-1 and containing the line (x-2)/3 =(1-y)/2 =(z+1)/1 is ax + by + gz = 24, then a + b + g is equal to :

(1) 20

(2) 19

(3) 18

(4) 21

Solution (3)

Problem 5: Let a computer program generate only the digits 0 and 1 to form a string of binary numbers with probability of occurrence of 0 at even places be ½  and probability 1  of occurrence of 0 at the odd place be ⅓. Then the probability that ‘10’ is followed by ‘01’ is equal to :

(1) 1/18

(2) 1/3

(3) 1/6

(4) 1/9

Solution (4)

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