A wire of resistance 10 Ω carries a current of 2 A. What is the potential difference across the wire?
Practice 2easy
The SI unit of electrical resistivity is:
Practice 3easy
Two resistors of 6 Ω and 12 Ω are connected in parallel. What is the equivalent resistance?
Practice 4easy
A conductor has a length of 2 m, cross-sectional area of 1 mm², and resistivity of 1.6 × 10⁻⁸ Ω·m. Calculate its resistance.
Practice 5easy
If the current through a resistor is doubled while keeping resistance constant, how does the power dissipated change?
Practice 6medium
Three resistors of 5 Ω, 10 Ω, and 15 Ω are connected in series across a 60 V battery. What is the total current in the circuit?
Practice 7medium
A wire of resistance 10 Ω carries a current of 2 A. What is the potential difference across the wire?
Practice 8medium
The resistivity of a conductor depends on which of the following factors?
Practice 9medium
A copper wire of length 2 m and cross-sectional area 1 mm² has resistivity 1.6 × 10⁻⁸ Ω·m. Calculate its resistance.
Practice 10medium
A wire has resistance R at 20°C. If its resistance at 100°C is 1.2R, what is the temperature coefficient of resistance?
Practice 11medium
A battery of EMF 12 V and internal resistance 2 Ω is connected to an external resistance of 4 Ω. What is the terminal voltage of the battery?
Practice 12medium
According to Kirchhoff's current law, at a junction in a circuit, what must be true?
Practice 13medium
A heating element draws a current of 5 A at 220 V. What is the power dissipated as heat?
Practice 14medium
Two resistors of 20 Ω and 30 Ω are connected in parallel. What is their equivalent resistance?
Practice 15hard
Three resistors of 6 Ω, 4 Ω, and 12 Ω are connected in parallel across a 24 V source. What is the total current drawn from the source?
Practice 16hard
A heater element draws 5 A current when connected to a 220 V supply. If the element is cut into two equal pieces and both are connected in parallel to the same supply, what is the new current drawn?
Practice 17hard
The resistivity of a conductor is 2 × 10⁻⁶ Ω·m. A wire made from this material has length 5 m and diameter 1 mm. What is its resistance?
Practice 18hard
A wire of resistance 10 Ω is stretched to double its original length. If the resistivity and density remain constant, what is the new resistance?