Secondary School (English Medium) (5 to 8) इयत्ता ७ - CBSE Question Bank Solutions

Wrap a thin paper strip tightly around an iron rod. Try to burn the paper with candle while rotating the iron rod continuously. Does it burn? Explain your observation.

Take a sheet of paper. Draw a spiral on it as shown in Figure. Cut out the paper along the line. Suspend the paper as shown in Figure above a lighted candle. Observe what happens. Think of an explanation.

Take two similar transparent glass bottles having wide mouths. Put a few crystals of potassium permanganate or pour a few drops of ink in one bottle. Fill this bottle with hot water. Fill the other bottle with cold water. Cover the cold water bottle with a thick piece of paper such as a postcard. Press the postcard firmly with one hand and hold the bottle with the other hand. Invert the bottle and place it on top of the hot water bottle. Hold both the bottles firmly. Ask some other person to pull the postcard. Observe what happens. Explain.

Using an electromagnet, you can make a working model of a railway signal as shown in figure.

Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.

State the differences between acids and bases.

The blood from the heart is transported to all parts of the body by the ______.

Haemoglobin is present in ______ cells.

Why is blood needed by all the parts of a body?

Describe the function of the heart.

Untreated human excreta is a health hazard. Explain.

Explain the relationship between sanitation and disease.

Outline your role as an active citizen in relation to sanitation.

Stomach of human beings mainly digests ______.

The acid present in the stomach ______.

Mark the following statement as True or False. If false, write the correct statement.

Mucus protects the stomach lining from damage.

Choose the odd one out from the group and give reason.

State whether the following statement is True or False. Correct the false statement.

Tropical rain forests are cool and humid throughout the year because of heavy rains all the time.

Which of the following place is most likely to be affected by a cyclone?

Why is Chandigarh unlikely to be affected by a cyclone?