Govt. Exams
Drift velocity is typically 10⁻⁴ to 10⁻³ m/s, much smaller than electron thermal velocity or speed of electrical signal
Resistivity is an intrinsic property dependent on the material's nature and temperature, not on the dimensions or electrical parameters
For parallel: 1/R_eq = 5×(1/5) = 1, so R_eq = 1Ω
Both balance condition and null point refer to the same situation where no current flows through the galvanometer
Constantan (copper-nickel alloy) has the lowest temperature coefficient of resistance, making it ideal for standard resistors
From Ohm's law: I = V/R. If I increases with increasing V while R stays constant, then the relationship is proportional and follows Ohm's law
P = V²/R = (10)²/5 = 100/5 = 20W
In parallel combination, all resistors are connected across same two points, hence voltage across each is same
A rheostat is a variable resistor used to control and vary the current in a circuit
In series: Total EMF = 1.5 + 1.5 + 1.5 = 4.5V. Total internal resistance = 1 + 1 + 1 = 3Ω
