JEE Main 2025 · 4 Apr 2025 Shift 1

In an experiment with a closed organ pipe, it is filled with water by (1/5)th of its volume. The frequency of the fundamental note will change by

1. A20%
2. B25%
3. C−20%
4. D−25%

In an electromagnetic system, the quantity representing the ratio of electric flux and magnetic flux has dimension of MᴾLQTRᴬS, where value of ‘Q’ and ‘R’ are

1. A(−2, 2)
2. B(1, −1)
3. C(3, −5)
4. D(−2, 1)

Which of the following are correct expression for torque acting on a body?

1. Aτ⃗ = r⃗ × L⃗
2. Bτ⃗ = d/dt (r⃗ × p⃗)
3. Cτ⃗ = r⃗ × dp⃗/dt
4. Dτ⃗ = I α⃗
5. Eτ⃗ = r⃗ × F⃗ (r⃗ = position vector; p⃗ = linear momentum; L⃗ = angular momentum; α⃗ = angular acceleration; I = moment of inertia; F⃗ = force; t = time) Choose the correct answer from the options given below:

A body of mass m is suspended by two strings making angles θ₁ and θ₂ with the horizontal ceiling with tensions T₁ and T₂ simultaneously. T₁ and T₂ are related by T₁ = √3T₂, the angles θ₁ and θ₂ are

1. Aθ₁ = 30° θ₂ = 60° with T₂ = 4mg/5
2. Bθ₁ = 60° θ₂ = 30° with T₂ = mg/2
3. Cθ₁ = 45° θ₂ = 45° with T₂ = 3mg/4
4. Dθ₁ = 30° θ₂ = 60° with T₂ = 3mg/4

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R Assertion A: The kinetic energy needed to project a body of mass m from earth surface to infinity is 1/2 mgR, where R is the radius of earth. Reason R: The maximum potential energy of a body is zero when it is projected to infinity from earth surface. In the light of the above statements, choose the correct answer from the options given below

1. ABoth A and R are true and R is the correct explanation of A
2. BBoth A and R are true but R is NOT the correct explanation of A
3. CA is true but R is false
4. DA is false but R is true

If L⃗ and P⃗ represent the angular momentum and linear momentum respectively of a particle of mass 'm' having position vector as r⃗ = a(î cos ωt + ĵ sin ωt). The direction of force is

1. AOpposite to the direction of r⃗
2. BOpposite to the direction of P⃗
3. COpposite to the direction of L⃗
4. DOpposite to the direction of L⃗ × P⃗