JEE Main 2023 Question Paper (31-Jan-2023) (Shift 2)

Question 1

The $ H $ amount of thermal energy is developed by a resistor in $ 10 \ \mathrm{s} $ when a current of $ 4 \ \mathrm{A} $ is passed through it. If the current is increased to $ 16 \ \mathrm{A} $, the thermal energy developed by the resistor in $ 10 \ \mathrm{s} $ will be

Accepted Answer

$16H$

Answer

$H$

Answer

$\frac{H}{4}$

Answer

$4H$

Question 2

A body is moving with constant speed in a circle of radius $10 \ \mathrm{m}$. The body completes one revolution in $4 \ \mathrm{s}$. At the end of the $3^	ext{rd}$ second, the displacement of the body (in $\mathrm{m}$) from its starting point is:

Accepted Answer

$10 \sqrt{2}$

Answer

$30$

Answer

$15 \quad \pi$

Answer

$5 \quad \pi$

Question 3

A microscope is focused on an object at the bottom of a bucket. If liquid with refractive index $ \frac{5}{3} $ is poured inside the bucket, then the microscope has to be raised by $ 30\,\mathrm{cm} $ to focus on the object again. The height of the liquid in the bucket is :

Accepted Answer

$75\,\mathrm{cm}$

Answer

$50\,\mathrm{cm}$

Answer

$18\,\mathrm{cm}$

Answer

$12\,\mathrm{cm}$

Question 4

A stone of mass $1\,\mathrm{kg}$ is tied to the end of a massless string of length $1\,\mathrm{m}$. If the breaking tension of the string is $400\,\mathrm{N}$, then the maximum linear velocity the stone can have without breaking the string, while rotating in the horizontal plane, is:

Accepted Answer

$20 \quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$\quad 40 \quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$400\quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$10\quad \mathrm{m} \quad \mathrm{s}^{-1}$

Question 5

For a solid rod, the Young's modulus of elasticity is $3.2 \times 10^{11} \ \mathrm{N} \ \mathrm{m}^{-2}$ and the density is $8 \times 10^{3} \ \mathrm{kg} \ \mathrm{m}^{-3}$. The velocity of the longitudinal wave in the rod will be

Accepted Answer

$18.96 	imes 10^{3} \quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$145.75 	imes 10^{3} \quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$3.65 	imes 10^{3} \quad \mathrm{m} \quad \mathrm{s}^{-1}$

Answer

$6.32 	imes 10^{3} \quad \mathrm{m} \quad \mathrm{s}^{-1}$