The first row of a certain determinant has the numbers 3 and 5. The second row has the numbers 7 and 2. The value of this determinant is
Answer: Option D
Explanation:
Determinant formula = |ad-bc|. Here a=3, b=5, c=7, d=2. (3*2)-(7*5) = -29. Answer = -29.
Using the mesh current method, find the branch current, IR1, in the above figure.
Answer: Option A
Nodal Equation=>((va-12)/68)+(va/37)+((Va-4)/90)=0 Va=4.180volt Ir1=((12-Va)/68) = (12-4.18)/68 =115mA
In assigning the direction of branch currents,
Answer: Option B
What is the voltage drop across R1?
Use Kirchhoff's Current Law (KCL).
Voltage drop across R1 = (12-Va). Va = 4.18. So VR1 = (12-4.18) = 7.82.
Find the node voltage VA.
Using kirchoff's current law at node A, ((Va-15)/68)+((Va/30))+((Va-8)/100)=0 (75Va-1125+170Va+51Va-408/5100)=0 296Va=1533 Va=5.179=5.18 volts
