AP EAMCET202418 May 2024Morning ShiftPhysicsCurrent ElectricityActual
In a potentiometer, the area of cross section of the wire is 4 ~cm ^2 , the current flowing in the circuit is 1 A and the potential gradient is 7.5 Vm ⁻¹ , then the resistivity of the potentiometer wire is
Options
- A3 10⁻³ ~m
- B2 10⁻⁶ ~m
- C4 10⁻² ~m
- D5 10⁻⁴ ~m
Correct answer
A. 3 10⁻³ ~m
Step-by-step solution
In potentiometer, A =4 ~cm ^2=4 10⁻⁴ ~m ^2 I =1 ~A , k =7.5 Vm ⁻¹ Potential gradient, k= V l = I_ A Resistivity = kA I = 7.5 4 10⁻⁴ 1 =3 10⁻³ ~m .