a cell of emf 10v and internal resistance 2ohms is connected in series with an ammeter resistance 0.5ohms and a load of resistance 7ohms. Calculate (A) the potential difference across its terminal (B)the voltage drop
Voltage= Current X Resistance(ohms law)
V-the battery voltage
R-resistance in a circuit
V=IR
P=IV
P=V2/R, where 2 is an exponent
P=I2R, where 2 is an exponent
P=Power
q=CV
q=charge
C=Capacitance
V=voltage
(ohms law for capacitors)
Nt now.leta
To calculate the potential difference across the terminals and the voltage drop, we can use Ohm's Law and Kirchhoff's laws.
(A) The potential difference across the terminals:
1. In a series circuit, the total resistance is the sum of all the individual resistances. In this case, it would be the sum of the internal resistance (2 ohms), the ammeter resistance (0.5 ohms), and the load resistance (7 ohms).
Total resistance (R_total) = 2 ohms + 0.5 ohms + 7 ohms = 9.5 ohms
2. According to Kirchhoff's voltage law, the sum of the voltage drops across each component in a series circuit is equal to the total potential difference across the circuit.
Voltage drop across the internal resistance (V_internal) = internal resistance (R_internal) * current (I)
Voltage drop across the ammeter resistance (V_ammeter) = ammeter resistance (R_ammeter) * current (I)
Voltage drop across the load resistance (V_load) = load resistance (R_load) * current (I)
Adding all the voltage drops together, we get:
V_terminal = V_internal + V_ammeter + V_load = (R_internal + R_ammeter + R_load) * I
3. We can use Ohm's Law to find the current (I) in the circuit:
I = emf (E) / total resistance (R_total) = 10 V / 9.5 ohms
4. Substituting the values back into the equation, we can calculate the potential difference across the terminals:
V_terminal = (R_internal + R_ammeter + R_load) * I = (2 ohms + 0.5 ohms + 7 ohms) * (10 V / 9.5 ohms)
(B) The voltage drop:
The voltage drop is the potential difference across a specific component. In this case, if we want to find the voltage drop across the load resistance (V_load), we use Ohm's Law:
V_load = R_load * I = 7 ohms * (10 V / 9.5 ohms)
To calculate the potential difference across the terminals and the voltage drop, substitute the values and calculate the expressions.