NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice
In a closed circuit, the current I (in ampere) at an instant of time t (in second) is given by I = 4 - 0.08 t . The number of electrons flowing in 50s through the cross-section of the conductor is
Options
- A1.25 × 10 19
- B6.25 × 10 20
- C5.25 × 10 19
- D2.55 × 10 20
Correct answer
B. 6.25 × 10 20
Step-by-step solution
I = 4 - 0.08 t A Or d q d t = 4 - 0.08 t A o r q = ∫ 0 50 4 - 0.08 t d t C o r N e = 4 t - 0.08 t 2 2 0 50 = 100 C Where N is number of electrons. or N = 100 e = 100 1.6 × 10 - 19 = 6.25 × 10 20