Determination of resistance of Galvanometer by half deflection method.
Apparatus: A low resistance galvanometer, a cell, two resistance box, two one way plug keys, connecting wires and sand paper. Theory: Set the circuit according to the figure. When only K, is closed the current .Through galvanometer is Where G resistance of galvanometer E = e.m.f of cell As current is proportional to the […]
Study of the variation in magnetic field strength along the axis of a current crying circular coil.
Apparatus: Stewart and gee’s type galvanometer, batter, ammeter, rheostat, one way plug key, reversing Ley connecting wires and sand paper, Stewart and Gee’s tangent galvanometer It consist of a circular coil of several turns of thin undulated copper wire wound on a wooden Game and fixed on a horizontal base with its plane vertical. The […]
Study of the relation between current passing through a tungsten filament and potential across it.
Apparatus: Battery (12 volts), tungsten lamp (12 volts, 25 watt), rheostat, voltmeter, ammeter, key, connecting wires and sand paper. Theory According to Ohm’s law, when potential difference across the resistances, the current also increases. This means that current and voltage are directly proportional to each other. But for tungsten filament Ohm’s Law does not hold […]
Determine the emf of a cell using a potentiometer
Apparatus: Potentiometer, battery (3 volts), leclanche cell, galvanometer, rheostat, one way key, two way key, voltmeter, connecting wires and sand paper Theory When k1of the two way key is closed, the emf E1 of cell is proportional to the balance length l1 when K2 of the two way key is closed, the unknown emf Eof […]
Study of the variation in resistance of thermistor with thermometer.
Apparatus: Thermistor, beak, tripod stand, boiling tube containing paraffin, spirit lamp, thermometer, voltmeter, ammeter, power supply and connect wires. Theory: Thermistor is a semiconductor whose resistance changes with temperature. Thermistor have negative temperature co-effect of resistance, thus their resistance decreases with the increase of temperature and vice versa. Highly temperature sensitive thermistors are used for […]
Study of variation of photo electric current with intensity of light.
Apparatus: Photocell, battery, key, micro ammeter or galvanometer, electric lamp, ruler and conne wires. Theory: In photocell an electric current is produced by the photo electric effect. It consists of t electrodes a plan cathode coated with a suitable photo-sensitive material and anode that is maintain at positive potential with respect to the cathode. The […]
Construction of burglar alarm using “NOT” gate.
Apparatus: NOT gate, thermistor (e.f. GM472 or VA 3404) variable resistor, power supply (6V), buzzer Theory: The thermistor is a device whose resistance changes by temperature. The resistance of a thermistor mases with increasing temperature. If we replace the LDR by a thermistor in the potential der circuit and apply it to NOT gate. We […]
Construction of burglar alarm using “NAND” gate.
Apparatus: CRP123 power supply (6V), variable resistor (100k), NAND gate, buzzer bread board. Theory: NAND gate is the combination of AND gate followed by NOT gate (inverter). The of NAND gate is high of anyone or more of the inputs are low. The symbol for AND gate is shown in figure. A small circle with […]
Verified of truth table for “NOT” Gate.
Apparatus: An npn transistor (BC547A), two resistors 1-2 and 20, 30k, power supply (SV), connecting wires, two-way key, LED and a bread board. Theory: NOT gate is a special gate having one input and output. It is also called inverter because it changes a high input to low input and vice versa. The symbol for […]
Verification of truth table for ‘OR” Gate.
Apparatus: Two semiconductor diode (SD-1), power supply (SV), resistance 4.7k, LED, 2 two-way keys. Theory The “OR” gate is an electronic circuit with two or more inputs and one output. The output is high or at I if any one or more input are high or at state 1. The symbol of two input ‘OR” […]
