- AWork done in taking a unit positive charge once round the circuit.
- BThe open circuit voltage of the cell.
- CThe terminal voltage when the current is zero.
- DAll the above.
Explanation:
EMF of cell can be defined as:
→ Workdone in taking unit positive charge once round the circuit.
→ The open circuit voltage of cell.
→ The terminal voltage when current is zero.
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Equal potentials are applied on an iron and copper wire of same length. In order to have the same current flow in the two wires, the ratio r (iron)/r (copper) of their radii must be (Given that specific resistance of iron =
ohm–m and specific resistance of copper = 1.7
ohm-m)
|
(a) About 1.2 |
(b) About 2.4 |
(c) About 3.6 |
(d) About 4.8 |
A diverging beam of light from a point source S having divergence angle a, falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is t and the refractive index n, then the divergence angle of the emergent beam is

|
(a) Zero |
(b) α |
(c) |
(d) 2 |
A moving conductor coil in a magnetic field produces an induced e.m.f. This is in accordance with
|
(a) Amperes law |
(b) Coulomb law |
(c) Lenz’s law |
(d) Faraday’s law |
The resistance and inductance of series circuit are 5
and 20H respectively. At the instant of closing the switch, the current is increasing at the rate 4A - s. The supply voltage is
|
(a) 20 V |
(b) 80 V |
(c) 120 V |
(d) 100 V |
Intensity of an electric field E due to a dipole, depends on distance r as
|
(a) E ∝ |
(b) E ∝ |
(c) E ∝ |
(d) E ∝ |
On an electric heater 220 volt and 1100 watt are marked. On using it for 4 hours, the energy consumed in kWh will be
|
(a) 2 |
(b) 4.4 |
(c) 6 |
(d) 8 |