Question

In a region of constant potential, (a) the electric field is uniform (b) the electric field is zero (c) there can be no charge inside the region (d) the electric field shall necessarily change, if a charge is placed outside the region

Polaroid glasses is used in sun glasses because : a. It reduces the light intensity to half on account of polarization b. It is fashionable c. It has good colour d. It is cheaper

A conducting rod of unit length moves with a velocity 10 m/s in a direction perpendicular to its length and perpendicular to a uniform magnetic field of magnitude 0.2 T. The emf induced between the ends of the rod is (a) 4 V (b) 2V (c) 1V (d) Zero

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

The dimensional representation of \(ε_0\) will be A. [\(MLT^2\)\(A^2\)] B. [\(M^{-1}\) \(L^{-3}\) \(T^4\) \(A^2\)] C. [\(ML^{-2}\)\(T^2\) \(A^{-2}\)] D. none of these

The capacitance of earth, viewed as a spherical conductor of radius 6408 km is: (a) 1420 μF (b) 712 μF (c) 680 μF (d) 540 μF

The figure below shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.04 V (for very moderate currents up to a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of 600 KΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf Ꜫ and the balance point, found similarly, turns out to be at 82.3 cm length of the wire. What is the value Ꜫ? (a) 0.25 V (b) 2.25 V (c) 3.25 V (d) 1.25 V