Reference no: EM131091609

Question: 1:

The Voltage V across an inductor L, in LR electrical circuit drops exponentially over time t(s)

The relationship is V=Ee^-1/τ . Where the emf, E and τ are constants. Use the table of values for t and v and logarithms to plot an appropriate straight line graph

t	0.00	0.010	0.020	0.025	0.030	0.040	0.050
v	5.0	2.350	1.400	1.050	0.750	0.550	0.350

Question:2

The amount of solute that will dissolve in a given volume of water depends on the temperature of the water. For a particular substance it is believed that the amount that will dissolve in 10 litres of water is governed by relationship:

m = Ae^kθ Where θ is the water temperature and A and k are constants. An experiment was performed to test this hypothesis and the following data was recorded.

temperature	10	20	30	40	50	60	70
Mass	4.72	5.32	6.02	7.83	8.77	9.87	10.14

Plot a linear graph which confirms that the relationship is exponential

Find the values of A and K.

Question: 3

The following data are for cold worked carbon steel tested in a tensile test:
Original diameter: 12.78 mm
Final diameter: 8.43 mm
Original gauge length: 49.8 mm
Final gauge length: 61.51 mm

Load (kN)	5.5	11.7	17.0	27.4	40.5	53.1	60.5	64.7	66.9
Extension	0.010	0.020	0.030	0.040	0.050	0.076	0.102	0.127	0.152

Load (kN)	68.7	70.5	71.5	72.1	72.8
Extension	0.203	0.254	0.305	0.356	0.508

The maximum load was 75.1 Kn. Plot the stress-strain graph and determine

a. Realistic estimation of the modulus of elasticity.

b. Relationship between stress and strain.

Question: 4

The electric current charging a capacitor is related to time by the following law.

I = 10 (1-e^-t/2)

Calculate the charge Q (area under the graph) between the limits t=0 and t=6 seconds. Use calculus trapezoidal rule.