JEE Physics Mock Test 1

Solution

Correct: B

Time period (T) of a simple pendulum is given by T = 2π √(l/g), where l is the length of the pendulum and g is the acceleration due to gravity. Given, l = 1 m, g = 9.8 m/s^2. Substituting these values in the equation gives T = 2π √(1/9.8) = 2 s.

Solution

Correct: B

Using the formula F = ma, we can calculate the mass of the body: m = F/a = 10/2 = 5 kg. Now, if the force is increased to 15 N, the new acceleration can be found using the same formula: a = F/m = 15/5 = 3 m/s^2.

Solution

Correct: B

Momentum (p) is given by p = mv, where m is the mass and v is the velocity. The change in momentum (Δp) is given by Δp = F × Δt, where F is the force applied and Δt is the time for which the force is applied. Given, F = 5 N, Δt = 2 s. So, Δp = 5 × 2 = 10 kg m/s.

Solution

Correct: C

Using the equation of motion v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration and t is the time. First, find the acceleration: a = F/m = 10/5 = 2 m/s^2. Now, v = 2 + 2 × 2 = 6 m/s.

Solution

Correct: A

Using the law of conservation of momentum: m1v1 + m2v2 = (m1 + m2)v. Given, m1 = 1 kg, v1 = 2 m/s, m2 = 2 kg, v2 = 3 m/s. Substituting these values gives: 1 × 2 + 2 × 3 = (1 + 2)v. This simplifies to 8 = 3v, so v = 8/3 = 2.67 m/s.

Solution

Correct: B

Potential energy (U) stored in a spring is given by U = 1/2 kx^2, where k is the force constant and x is the displacement. Given, k = 100 N/m, x = 2 m. Substituting these values gives U = 1/2 × 100 × (2)^2 = 200 J.

Solution

Correct: B

Kinetic energy (K) is given by K = 1/2 mv^2, where m is the mass and v is the velocity. Given, m = 10 kg, v = 5 m/s. Substituting these values gives K = 1/2 × 10 × (5)^2 = 125 J.

Solution

Correct: A

At the highest point, the velocity of the ball becomes zero because all its initial kinetic energy is converted to potential energy.

Solution

Correct: B

Work done (W) is given by W = F × s, where F is the force applied and s is the displacement. Given, F = 10 N, s = 2 m. Substituting these values gives W = 10 × 2 = 20 J.

Solution

Correct: B

Momentum (p) is given by p = mv, where m is the mass and v is the velocity. Given, m = 1000 kg, v = 20 m/s. Substituting these values gives p = 1000 × 20 = 20000 kg m/s.

Solution

Correct: A

Pressure (P) is given by P = F/A, where F is the force applied and A is the area. Given, F = 10 N, A = 2 m^2. Substituting these values gives P = 10/2 = 5 N/m^2.

Solution

Correct: B

The buoyant force (F) is given by F = ρVg, where ρ is the density of the fluid, V is the volume of the immersed object, and g is the acceleration due to gravity. Given, ρ = 1000 kg/m^3, V = (2)^3 = 8 m^3. Assuming g = 10 m/s^2, F = 1000 × 8 × 10 = 80000 N = 8000 × 10 N.

Solution

Correct: B

The force of friction (f) is given by f = μmg, where μ is the coefficient of friction, m is the mass, and g is the acceleration due to gravity. Given, f = 10 N, m = 5 kg, assuming g = 10 m/s^2. Rearranging the equation to solve for μ gives μ = f/mg = 10/(5*10) = 0.2.

Solution

Correct: B

Speed (v) is given by v = distance/time. Given, distance = 20 m, time = 2 s. Substituting these values gives v = 20/2 = 10 m/s.

Solution

Correct: B

Frequency (f) is given by f = v/λ, where v is the speed and λ is the wavelength. Given, v = 10 m/s, λ = 2 m. Substituting these values gives f = 10/2 = 5 Hz.

Solution

Correct: B

Momentum (p) is given by p = mv, where m is the mass and v is the velocity. Given, m = 2 kg, v = 3 m/s. Substituting these values gives p = 2 × 3 = 6 kg m/s.

Solution

Correct: B

Work done (W) is given by W = F × s, where F is the force applied and s is the displacement. Given, F = 5 N, s = 6 - 2 = 4 m. Substituting these values gives W = 5 × 4 = 20 J.

Solution

Correct: B

Change in momentum (Δp) is given by Δp = F × Δt, where F is the force applied and Δt is the time for which the force is applied. Given, F = 10 N, Δt = 2 s. Substituting these values gives Δp = 10 × 2 = 20 kg m/s.

Solution

Correct: B

Potential energy (U) stored in a spring is given by U = 1/2 kx^2, where k is the force constant and x is the displacement. Given, k = 50 N/m, x = 4 m. Substituting these values gives U = 1/2 × 50 × (4)^2 = 400 J.

Solution

Correct: B

Kinetic energy (K) is given by K = 1/2 mv^2, where m is the mass and v is the velocity. Given, m = 5 kg, v = 2 m/s. Substituting these values gives K = 1/2 × 5 × (2)^2 = 10 J.

Solution

Correct: A

At the highest point, the velocity of the ball becomes zero because all its initial kinetic energy is converted to potential energy.

Solution

Correct: C

Momentum (p) is given by p = mv, where m is the mass and v is the velocity. Given, m = 1500 kg, v = 25 m/s. Substituting these values gives p = 1500 × 25 = 37500 kg m/s.

Solution

Correct: B

Pressure (P) is given by P = F/A, where F is the force applied and A is the area. Given, F = 20 N, A = 5 m^2. Substituting these values gives P = 20/5 = 4 N/m^2.