Physics Test 17...

Total electric force on an electric dipole placed in an electric field of a point charge is:

The magnitude of magnetic field at O (centre of the circular part) due to the current carrying coil as shown is :

Eight point charges (can be assumed as small spheres uniformly charged and their centres at the corner of the cube) having values q each are fixed at vertices of a cube. The electric flux through square surface ABCD of the cube is

A charged particle is moving in the region around a long current carrying wire. Due to wire, it may experience:

The figure shows a charge q placed  inside a cavity in an uncharged conductor. 

Now if an external electric field is switched on :

Two infinite sheets carrying current in same direction  (of equal current per unit length K) are separated by a distance ‘d’. A proton is released from a point between the plates with a velocity parallel to the sheets but perpendicular to the direction of current in the sheets. Then the path of the proton is 

Three large parallel charged conducting plates are placed at a small distance d apart from each other. The surface charge density on the face B of the conductor is +5.0 ε_o coulomb/m² and that on face E is + 6.0 ε_o columb/m². Charges on other faces are not known. The electric field intensity at P (shown in the figure) between the plates is

A horizontal metallic rod of mass 'm'  and length  ' l '  is supported by two vertical identical springs of spring constant 'K'  each and natural length  l​₀. A current  ' i ' is flowing in the rod in the direction shown. If the rod is in equilibrium then the length of each spring in this state is:

A 150 m long metal wire connects points A and B. The electric potential at point B is 50 V less than that at point A. If the conductivity of the metal is 60 × 10⁶ mho/m, then magnitude of the current density in the wire is equal to :

A toroid of mean radius ' a ' , cross section radius ' r ' and total number of turns N. It carries a current ' i '. The torque experienced by the toroid if a uniform magnetic field of strength B is applied :