First, the pulley block with simple assembly
Material: two pulleys (thin wire, iron frame, several hooks).
Score point: 1, fix a pulley on the iron frame;
2. Tie one end of the thin thread to the pulley hook;
3, win that other end of the thin wire on two pulleys to assemble a pulley block;
4. Hang the hook code and pull the free end of the thin thread at a uniform speed, and the pulley block can work normally;
5. After the experiment, tidy up the equipment.
2. Weigh the mass of solid with a balance.
Equipment: an unbalanced pallet balance (supporting weight box) with five solids.
Score point: (1) can correctly adjust the balance.
(2) When weighing, the weighed object is placed on the left plate and the weight is placed on the right plate.
(3) Balance the balance by increasing or decreasing the weight and moving the position code (using tweezers).
(4) The measurement results can be recorded correctly.
(5) After the experiment, tidy up the equipment.
3. Turn the convex lens into an inverted and reduced real image.
Equipment: convex lens (indicating focal length), concave lens (also indicating focal length), candle, light curtain, optical bench and matches.
Scoring point: (1) Correct selection of equipment.
(2) The position of candle, convex lens and light screen can be correctly fixed on the optical bench.
(3) Adjust the heights of the convex lens and the shading plate so that their centers are approximately at the same height as the center of the candle flame.
(4) Correct operation makes a clear candle flame image (inverted and reduced real image) appear on the screen.
(5) After the experiment, tidy up the equipment.
4. Connect the series circuit and measure the voltage value of one of the appliances.
Equipment: battery box (containing 2-3 dry batteries), 1 switch, 2 small bulbs (with lampholders), 1 voltmeter and several wires.
Score point: 1. When the circuit is connected, the switch should be closed;
2, can correctly connect the series circuit, and check;
3, can correctly access the voltmeter;
4, correctly read and record the voltage value of electrical appliances;
5. After the experiment, tidy up the equipment.
5. Measure the rated power of the small bulb.
Equipment: battery box (containing 2-3 dry batteries), 1 switch, 1 small bulb (with lamp cap), one voltmeter and ammeter, one sliding rheostat and several wires.
Score point: (1) When the circuit is connected, the switch should be turned off.
(2) The series circuit can be connected correctly, and the ammeter, voltmeter and sliding rheostat can be connected correctly and checked correctly.
(3) The sliding blade of the sliding rheostat can be adjusted to make the voltage at both ends of the bulb reach the rated voltage (reading is correct, 2.5V).
(4) Correctly read and record the current value passing through an electrical appliance, and calculate the rated power of the small light bulb.
(5) After the experiment, tidy up the equipment.
Scoring requirements: according to the scoring score, one operation is correct 1, two operations are correct, and five operations are correct, with full marks (5 points).