A capacitor is connected across a battery and the plate separation of capacitor is increased without removing the battery, then: (a) capacitance will increase (b) charge stored will increase (c) energy stored will decrease (d) potential difference will increase

A charge q is placed at one corner of the cube. The electric flux passing through any one of its face is

A charge Q is placed at the origin. The electric potential due to this charge at a given point in space is V. The work done by an external force in bringing another charge q from infinity up to the point is (a) v/q (b) vq (c) v+q (d) v

A coil of wire of certain radius has 500 turns and self inductance of 75 mH. The self inductance of a second similar coil of 600 turns will be (a) 100 mH (b) 150mH (c) 108 mH (d) 105mH

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

A current carrying small loop behaves like a small magnet. If A be its area and M its magnetic moment, the current in the loop will be a) M/A b) A/M c) MA d) A²M

A current loop placed in a magnetic field behaves like a a) Magnetic substance b) Magnetic pole c) Magnetic dipole d) all true

A deuteron of kinetic energy 50 keV is describing a circular orbits of radius 0.5 m in a plane perpendicular to the magnetic field B . The kinetic energy of the proton that describes a circular orbit of same radius and inside same B is- (a) 25 kev (b) 50 kev (c) 200 kev (d) 100 keV

A dielectric induces....... in an external electric field which decreases the net electric field. (a) current (b) dipole moment (c) magnetic field (d) polarisation

A dip circle is so set that it moves freely in the magnetic meridian. The angle of dip is 40°. Now the dip circle is rotated so that the plane in which the needle moves makes an angle of 30° with the magnetic meridian. In this position, the needle will dip by the angle

A long solenoid has 2000 turns. When a current of 2 A flows through it, then the magnetic flux linked with each turn of the solenoid is 2 × 10⁻³ Wb. The self inductance of the solenoid is (a) 1 H (b) 2 H (c) 3 H (d) 4 H

A network of resistors is connected to a 16 V battery with internal resistance of 1Ω as shown in the Fig. Compute the equivalent resistance of the network. (a) 5 ohm (b) 7 ohm (c) 9 ohm (d) 10 ohm

A parallel plate air capacitor has a capacitance 18μF. If the distance between the plates is tripled and a dielectric medium is introduced, the capacitance becomes 72μF. The dielectric constant of the medium is (a) 4 (b) 9 (c) 12 (d) 2

A parallel plate capacitor is made by stacking n equally spaced plates connected alternately. If the capacitance between any two plates is C, then the resultant capacitance is (a) C (b) nC (c) (n-1)C (d) (n+1)C

A resistance of R Ω draws current from a potentiometer. The potentiometer has a total resistance \(R_0\) Ω as shown in the Fig below. A voltage V is supplied to the potentiometer. Derive an expression for the voltage across R when the sliding contact is in the middle of the potentiometer.