1
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Given below are two statements :

Statement (I): It is impossible to specify simultaneously with arbitrary precision, both the linear momentum and the position of a particle.

Statement (II) : If the uncertainty in the measurement of position and uncertainty in measurement of momentum are equal for an electron, then the uncertainty in the measurement of velocity is $\geqslant \sqrt{\frac{h}{\pi}} \times \frac{1}{2 m}$.

In the light of the above statements, choose the correct answer from the options given below :

A

Statement I is false but Statement II is true

B

Both Statement I and Statement II are true

C

Both Statement I and Statement II are false

D

Statement I is true but Statement II is false

2
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Total number of sigma (σ) _______ and pi(π) ______ bonds respectively present in hex-1-en-4-yne are:

A

14 and 3

B

11 and 3

C

13 and 3

D

3 and 13

3
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Which among the following halides will generate the most stable carbocation in the nucleophilic substitution reaction?

A
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 19 English Option 1
B
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 19 English Option 2
C
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 19 English Option 3
D
JEE Main 2025 (Online) 29th January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 19 English Option 4
4
JEE Main 2025 (Online) 29th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Drug $X$ becomes ineffective after $50 \%$ decomposition. The original concentration of drug in a bottle was $16 \mathrm{mg} / \mathrm{mL}$ which becomes $4 \mathrm{mg} / \mathrm{mL}$ in 12 months. The expiry time of the drug in months is _________.

Assume that the decomposition of the drug follows first order kinetics.

A

12

B

3

C

6

D

2

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