Two balls carrying charges - and +8 attract each other with a force F. If a charge of -3 is added to both the balls, then the force between then will become A. 2F B. F/2 C. F D. zero

what is the angle between an electric dipole moment and then electric field strength due to it on its equatorial line? (A) \(0^\circ\) (B) \(90^\circ\) (C) \(180^\circ\) (D) None of these

When a person standing barefoot on the ground comes in contact with a high-power line, he is likely to A. experience a total shock B. experience a mild shock C. experience a moderate shock D. remain unaffected

\(10^6\) electrons are taken out of a pith ball. The positive charges on the pith ball is A. 1.6x \(10^{-13}\) C B. 1.6x \(10^{-19}\) C C. 1.6x \(10^{-25}\) C D. none of these

Two charges of 2uC and 5uC are placed 2.5 cm apart. The ratio of Coulomb's force experienced by them is

A compass needle whose magnetic moment is 60 A m² pointing geographical north at a certain place, where the horizontal component of the earth’s magnetic field is 40 μWb m², experiences a torque 0.2 × 10⁻³ Nm. The declination at this place is

A conducting loop of area 5.0 cm² is placed in a magnetic field which varies sinusoidally with time as B=0.2 sin300t. The normal to the coil makes an angle of 60° with the field. The emf induced at t=(π/900)s (a) 7.5 × 10⁻³ V (b) Zero (c) 15 × 10⁻³ V (d) 20 × 10⁻³ V

A parrot comes and sits on a bare high-power line. It will A. experience a mild shock B. experiences a strong shock C. get killed instantaneously D. not be affected at all

A tiny spherical oil drop carrying a net charge q is balanced in still air with a vertical uniform electric field strength 81/7 x 10⁵ Vm⁻¹. When the field is switched off, the drop is observed to fall with terminal velocity 2 x 10⁻³ ms⁻¹, given g = 9.8 ms⁻², viscosity of the air = 1.8 x 10⁻⁵ Nsm⁻², and the density of oil = 900 kgm⁻¹. The magnitude of q is. (A) 1.6 x 10⁻¹⁹ C (B) 3.2 x 10⁻¹⁹ C (C) 4.0 x 10⁻¹⁹ C (D) 8.0 x 10⁻¹⁹ C

A vertical disc of radius 10 cm makes 10 revolutions per second about a horizontal axis passing through its centre. A uniform magnetic field 10⁻² T acts perpendicular to the plane of the disc. The potential difference between its centre and rim in volts is (a) 3.14 × 10⁻² V (b) 3.14 × 10⁻³ V (c) 6.28 × 10⁻² V (d) 6.28 × 10⁻³ V

Equal potentials are applied on an iron and copper wire of same length. In order to have same current flow in the wire, the ratio

If a magnet is cut perpendicular its length into equal parts ,then the pole strength of each pole of the magnet a) becomes double b) remains same c) becomes half d) None of the above

In a permanent magnet at room temperature, (a) magnetic moment of each molecule is zero (b) the individual molecules have non-zero magnetic moment which are all perfectly aligned (c) domains are partially aligned (d) domains are all perfectly aligned

In an interference pattern produced by two identical slits, the intensity at the site of maxima is I. When one of the slit is closed, the intensity at the same spot is I0. What is the relation between I and \(I_0\) (a) I = 2 \(I_0\) (b) I = 4 \(I_0\) (c) I = 16 \(I_0\) (d) I = \(I_0\)

In the phenomena of Diffraction of light when the violet light is used in the experiment is used instead of red light then. (a) Fringe width increases. (b) No change in fridge width. (c) Fringe width decreases. (d) Colour pattern is formed.