Practice Test - Physics 15

An inductor (L = 0.03 H) and a resistor (R = 0.15 kΩ) are connected in series to a battery of 15 V EMF in a circuit shown below. The key K _­1 has been kept closed for a long time. Then at t = 0, K₁ is opened and key K₂ is closed simultaneously. At t = 1 ms, the current in the circuit will be :

Two charges, each equal to q, are kept at x = −a and x = a on the x-axis. A particle of mass m and charge is placed at the origin. If charge q₀ is given a small displacement (y << a) along the y-axis, the net force acting on the particle is proportional to:

The work done in placing a charge of 8 × 10⁻¹⁸ coulomb on a condenser of capacity 100 micro-farad is

Initially both sphere & particle were at rest. They will collide with speed

A block is kept on a frictionless inclined surface with angle of inclination . The incline is given an acceleration a to keep the block stationary. Then a is equal to

Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly (surface tension of soap solution = 0.03 Nm^–1)

A boy playing on the roof of a 10 m high building throws a ball with a speed of 10 m/s at an angle of 30° with the horizontal. How far from the throwing point will the ball be at the height of 10 m from the ground?
[g = 10 m/s², sin 30° = ½, cos 30° = √3/2]