Physics - Online Test

Total  electric power required,  P =  800 kW

supply voltage V = 220 volt

voltage at which electric plant generating power V1 = 440 volt

distance between town and power generating station, d = 15 km

total resistance of two wire cable R = (15+15) x 0.5 = 15 ohm

input voltage of transformer Vi = 4000 volt

output voltage of transformer Vo = 220 volt

current in wire line 

i=PVi=800×1034000=200A

line power loss 

Ploss=i2R=200×200×15=600×103=600KW

The circuit is reduced to find equivalent resistance as follows;





In (1), 2Ω, 4 Ω, and 2 Ω are in series. Their equivalent resistance is 8 Ω. In (2), the two 8 Ω resistors are in parallel and their equivalent resistance is 4 Ω. In (3) 2 Ω, 4 Ω, and 2 Ω are in series. Their equivalent resistance is 8 Ω which is in parallel with the 8 Ω resistance as shown in (4). The total resistance in the circuit

R= 3+4+2+1( internal resistance)=10 Ω. The current through the 3 Ω resistor

I = E/R = 10/10

I = 1A

=1010I=1A

Acceleration is the rate of change of velocity of an object with respect to time.

a = change in velocitytime taken

SI unit of velocity = m/s

SI unit of time = s

So SI unit of acceleration = ms×s=m/s2