# Please Any Solve These Physics Problems For Me, Will Be Thankful.



## Bohiojk (Aug 24, 2014)

Please solve with steps and formulas 

(1) A generator produces 100 KW of power at the potential difference of 10 KV. The power is transmitted through cables of total resistance 5 ohms. How much power is transmitted/dissipated in cables
A) 50 W
B) 250 W
C) 500 W
D) 1000 W
E) 50000 W

(2) A parallel combination of three resistors take a current of 4.5 A from a 30 V battery. If the two of the resistances are 12 ohm and 10 ohm, the third one is;
A) 55 ohm
B) 35 ohm
C) 25 ohm
D) 15 ohm
E) 30 ohm

(3) One thousand watts of electric power are transmitted to a device by a means of two wires each of which has a resistance of 2 ohm. If the resulting P.D across the device is 100 V the P.D across the source supplying the power is;
A) 20 V
B) 40 V
C) 100 V
D) 140 V
E) 500 V

(4) When a resistance of 2 ohm is connected across the terminal of the cell is 0.5 Amp , but when the resistance across the cell is 5 ohm the current is 0.25 Amp. The emf of the cell is;
A) 2.0 V
B) 1.5 V
C) 1.0 V
D) 0.5 V
E) 7.0 V


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## Thrushe42 (Jun 18, 2014)

Is there something wrong with number 2? I keep on getting -30.

4) B (I think). 
The cell could have internal resistance (r). E= I (R+r) 
E= I1( R1+r) and E=I2 (R2+r) 
Equate them ... (0.5)(2+r)=(0.25)(5+r) => r= 1.
Substitute => E= 1.5 V.


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