2nd year Physics Practical Graphs

Important very easy 2nd year Physics Practical Graphs written by Miss Pakiza Waqar. These experiments are very helpful in the preparation of the 2nd Year Physics Practical Past Papers in Physics for the students and this is according to the Institute.

• Important Experimental Graphs taken out from Board Papers

How to find the slope of curved graph?

• Slope of straight line graph is constant which can be determined by taking any two points on the graph line while slope of curved graph changes from point to point. So, we can find slope at any point by drawing tangent at that point and then taking any two points on tangential line (as discussed above for straight line), finding x and y intercept and using the formula:  Slope = y2 - y1 / x2 - x1 , Slope = Δy / Δx
• Q.1: Draw a graph between t and x.
• Q.2: Draw a graph between t and S.
• Q.3: Draw a graph between m and T.
• Q.4: Draw a graph between t and V.
• Q.5: Draw a graph between L and ΔX.
• Q.6: Draw a graph between m (g) and T (s)
• Q.7: Draw a graph between L and T^2.
• Q.8: Draw a graph between 1 / p and 1 / q.
• Q.9: Draw a graph between F and x.
• Q.10: Draw a graph between √L and T.
• Q.11: Draw a graph between t and R.
• Q.12: Draw a graph between p + q and p q.
• Q.13: Draw a graph between V and Q.
• Q.14: Draw a graph between R ( Ω ) and 1 / v ( v^-1 ).
• Q.15: Draw a graph between R ( Ω ) and 1 / v ( v^1 ).
• Q.16: Draw a graph between V and I.
• Q.17: Draw a graph between C and I.
• Q.18: Draw a graph between 1  / d^2 and I.
• Q.19: Draw a graph between R - S ( Ω ) and R S ( Ω ).
• Q.20: Draw a graph between R - S ( Ω ) and R S.

EXPERIMENT NO. 1

• To determine the resistance of wire by slide wire bridge. Also, calculate the resistivity or specific resistance of the material of the wire.
• APPARATUS: Slide wire bridge, resistance box, galvanometer, battery, Resistance wire plug key, connecting wires, sand paper, Rheostat, screw gauge and Jockey circuit.
• PROCEDURE: First of all I drew circuit diagram, placed apparatus on table and made connections according to diagram. Then I took a suitable resistance R from resistance box and touched the jockey at end A and then at end C. I found opposite deflection on galvanometer which means connections are correct. I inserted resistance back in the resistance box. I again took out resistance R from box. I pressed jockey on wire of slide wire bridge at end A and observed deflection on galvanometer. Now I pressed jockey on wire at different positions between A and C. I found the balance point (zero deflection) at B which is somewhere in the middle of wire. I noted the length l1 = BC and l2 = AB. I calculated the value of unknown resistance by formula:  x = R I2 / I1 , I took three more observations by same procedure by changing value of resistance R and calculated mean resistance X.
• RESULT: It is found that the resistance of the given wire = X = 7.42 Ω  (Note: Mostly it is asked to calculate unknown resistance of the wire and not to find resistivity)
• ii) CALCULATION OF SPECIFIC RESISTANCE (OR RESISTIVITY):
• Length of the unknown resistance wire = L = 100 cm
• Diameter of the resistance wire = (i) 0.41 mm (ii) 0.41 mm (iii) 0.41 mm
• Mean diameter = D = 0.41 mm = 0.041 cm
• Radius of wire = r = D/2 = 0.0205 cm
• Area of cross-section of the resistance wire = A = πr²
• Resistivity = p = X πr² /L = 7.42x 3.14x (0.0205)² /100 0-cm = 9.8x105 Ω-cm
• RESULT: It is found that Specific resistance (or resistivity) of wire = 9.8x105 Ω-cm

PRECAUTIONS:

• Connections should be clean and tight.
• The wire under test should be free from kinks.
• The current passed should not be very strong and for much time.
• The portion of the wire inside the binding screw should be excluded in measuring its length.
• The jockey should not be pressed too much while sliding it over the wire.
• The battery circuit should be closed before the galvanometer circuit.