Electricity PYQs Solution PDF Download
All Formulas of Electricity:
1) I = Q/t
2) Q = ne
3) V = W/Q
4) V = IR
5) R = Rho x L/A
6)Resistance in Series: Rs = R1 + R2 + R3
7)Resistance in Parallel: 1/Rp = 1/R1 + 1/R2 + 1/R3 (» Reciprocal of R1+R2+R3)
8)H = V × Q i) H = VIt ii) H = I²Rt iii) H = V²t/R
9) P = W/t i) P = VI ii) P = I²R iii) P = V²/R
10) E = P × t S.I.
Units:
Current ( I ) – Ampere
Charge ( Q ) – Coulomb
Time ( t ) – Second
Potential Difference or Voltage ( V ) – Volt
Resistance ( R ) – Ohm Ω
Resistivity ( Rho ) – Ohm meter
Power ( P ) – Watt
Heat = Energy = Work = Joule
Measuring Devices:
Ammeter / Milli Ammeter – for measuring current (always connected in series)
Galvanometer – for measuring small/sensitive currents (we can also get the direction of the current)
Voltmeter – for measuring volts (always connected in parallel)
Ohm Meter – Measures the resistivity
Least Count = First Value/No. Of Divisions
Things to remember:
electron charge = (1.6 x 10⁻¹⁹ C)
1kWh= 3.6 × 10⁶J
1Ampere = 1000mA
1 Kilowaat = 1000W
1 Horse Power = 746W