Most Important Selected Qs for JEE AdvancedPhysicsMagnetic Effects of Current
Paragraph: Analog voltmeters and ammeters work by measuring the torque exerted by a magnetic field on a current carrying coil. The reading is displayed by means of the deflection of a pointer over a scale. The adjacent figure shows the essentials of a galvanometer, on which both analog ammeters and analog voltmeters are based. Assume that the coil is 2.1 cm high, 1.2 cm wide, has 250 turns and is mounted so that it c
Options
- A2.6 10⁻⁸ Nm / degree
- B5.2 10⁻⁸ Nm / degree
- C2.6 10⁻⁴ Nm / degree
- D5.2 10⁻⁴ Nm / degree
Correct answer
B. 5.2 10⁻⁸ Nm / degree
Step-by-step solution
=K K= = M B = niAB ~K = 250 100 10⁻⁶ 2.1 1.2 10⁻⁴ 0.23 28 =5.2 10⁻⁸ Nm /degree