Physics Test 19...

The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is

Suppose the charge of a proton and an electron differ slightly. One of them is -e, the other is (e+Δe). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then Δe is of the order of

[given ma of hydrogen mh = 1.67×10⁻²⁷kg]

A capacitor of 2 μF is charged as shown in the diagram. When the switch S is turned to position 2, the percentage of its stored energy dissipated is

An electric dipole is placed at an angle of 30° with an electric field intensity 2 × 105NC⁻¹.It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is

People living at sea level have around 5 million RBC per cubic millimeter of their blood whereas those living at an altitude to 5400 metres have around 8 million. This is because at high altitude

An electric bulb is rated 220 V–100 W. The power consumed by it when operated on 110 V will be

A (100 W, 200 V) bulb is connected to a 160 V power supply. The power consumption would be

The relation between current and drift velocity is

A conductor wire having 10²⁹ free electrons carries a current of 20 A. If the cross-section of the wire is 1 mm², then the drift velocity of electrons will be

The current passing through the ideal ammeter, in the circuit given below, is