Answer:
The time is 
Explanation:
Given that,
Capacitor = 120 μF
Voltage = 150 V
Resistance = 1.8 kΩ
Current = 50 mA
We need to calculate the discharge current
Using formula of discharge current

Put the value into the formula


We need to calculate the time
Using formula of current

Put the value into the formula





Hence, The time is 
Explanation:
It is given that,
Inductance,
RMS value of voltage,
Frequency, f = 60 Hz
We need to find the energy stored at t = (1 /185) s. It is assumed that energy stored in the inductor is zero at t = 0. So,
The current flowing through the inductor is given by :

I = 0.091 A
Energy stored in the inductor is, 

U = 0.000165 Joules
Hence, this is the required solution.
Answer:
The dynamo has a wheel that touches the back tyre. As the bicycle moves, the wheel turns a magnet inside a coil. This induces enough electricity to run the bicycle's lights. The faster the bicycle moves, the greater the induced voltage - and the brighter the lights.
Answer:
4th answer
Explanation:
The gradient of a distance-time graph gives the speed.
gradient = distance / time = speed
Here, the gradient is a constant till 30s. So it has travelled at a constant speed. It means it had not accelarated till 30s. and has stopped moving at 30s.
no, work is = force * distance or displacement