Force, Work, Power and Energy
Work, Power and Energy
Refraction of Light Through Plane Surface
Refraction of Light Through a Lense
Electricity and Magnetism
Electrical Power and Energy and Household Circuits
- Concept of Electrical Power and Household Circuits Numericals
- Household Circuits - Colour Coding of Wires
- Household Circuits - Three-pin Plugs
- Household Circuits - Safety Precautions
- Earthing (Grounding)
- Electric Switch
- Household Circuits – Main Circuit
- Electrical Energy and Power
- Electric Power
- Alternating Current (A.C.) Generator
- Current Electricity
- Resistors in Series
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
An electrical gadget can give an electric shock to its user under certain circumstances. Mention any two of these circumstances.
A wire of length 5 m has a resistance of 2.0 Ω calculate:
(a) the resistance of wire of length 1 m
(b) the equivalent resistance if two such wires each of length 2 m are joined in parallel.
(c) the resistance of 1 m length of wire of same material but of half diameter.
A cell supplies a current of 1.2 A through two 2 Ω resistors connected in parallel. When the resistors are connected in series, it supplies a current of 0.4 A. Calculate: (i) the internal resistance and (ii) e.m.f. of the cell.
Two wires of the same material and same length have radii r1 and r2 respectively compare: (i)
their resistances, (ii) their resistivities.
A switch must be connected in:
(a) Live wire (b) neutral wire
(c) earth wire (d) either earth or neutral wire