Physics Test 25...

A long infinite current-carrying wire is bent in the shape as shown in the figure. The magnetic induction at point O is:

A particle is projected with a velocity v so that its range on a horizontal plane is twice the greatest height attained If g is acceleration due to gravity, then its range is

A block of mass 30 kg is suspended by three strings as shown in figure. Find the tension in each string.

A block of mass 1 kg is at rest on a horizontal table. The coefficient of static friction between the block and the table is 0.50. If g = 10 ms⁻², then the magnitude of a force acting upwads at an angle of 60^∘ from the horizontal that will just start the block moving is:

A disc of mass m and radius R placed on a smooth horizontal table as shown in figure. A light ideal string passes through the disc such that the one end of the string is attached to a small body of mass m and the other end is being pulled with a force F. The circumference of the disc is sufficiently rough so that the string does not slip over it. Find acceleration of the small body.

A block of wood floats in a liquid with four-fifths of its volume submerged. If the relative density of wood is 0.8, what is the the density of the liquid in units of kgm⁻³?

The potential energy of a particle of mass 1 kg.in motion along the x-axis is given by: U = 4(1 − cos2x), where x is in metres. The period of small oscillation (in seconds) is

A point mass is subjected to two simultaneous sinusoidal displacements in the x-directions: x₁(t) = A sin ωt and x₂(t) = A sin(ωt + 2π/3). Adding a third sinusoidal displacement x(t) = B sin(ωt + ϕ) brings the mass to a complete rest. The values of B and ϕ are respectively

A positively charged ball hangs from a long silk thread. Electric field at a certain point (at the same horizontal level of the ball) due to this charge is E. Let us put a positive test charge q₀ at this point and measure F/q₀ on this charge. Then, E