Worksheets With Solutions: Electric Current and Its Effects Class 7 Worksheet Science Chapter 10

Section A: Multiple Choice Questions 

Correct Answer is Option (a)
Xylem is a type of tissue in plants that is responsible for the transport of water and minerals from the roots to the leaves. Phloem is another type of tissue that transports sugars and other organic compounds from the leaves to other parts of the plant.

Q.2. Which of the following is NOT a function of blood in animals?
(a) Transport of nutrients
(b) Transport of waste products
(c) Protection against diseases
(d) Production of energy

Correct Answer is Option (d)

Blood does not produce energy, but it does transport oxygen and nutrients to the body's cells, and it removes waste products such as carbon dioxide.

Q.3. Which of the following statements is true about electric circuits?
(a) A circuit with only one path for the current is called a parallel circuit.
(b) A circuit with more than one path for the current is called a series circuit.
(c) A circuit with no path for the current is called an open circuit.
(d) A circuit with a switch that can turn on or off the current is called a closed circuit.

Correct Answer is Option (b)
A circuit with only one path for the current is called a series circuit, while a circuit with more than one path is called a parallel circuit. A closed circuit is one that allows the current to flow, while an open circuit does not. A switch can be used to turn the current on or off in a closed circuit.

Q.4. Which of the following is a safety device used in electric circuits to protect against overloading?
(a) Electric motor
(b) Electric switch
(c) Electric fuse
(d) Electric generator

Correct Answer is Option (c)
An electric fuse is a safety device that is used to protect against overloading in an electric circuit. When the current in the circuit exceeds a certain level, the fuse breaks the circuit and stops the flow of electricity. This helps to prevent damage to the circuit or the devices that are connected to it.

Q.5. Which of the following materials is NOT attracted to a magnet?
(a) Iron
(b) Copper
(c) Nickel
(d) Cobalt

Correct Answer is Option (b)
Iron, nickel, and cobalt are all metals that are attracted to magnets. Copper is not magnetic and is therefore not attracted to magnets.

Section B: Short Questions

The heating effect of electric current can be used in many ways in our daily lives. For example, it is used in electric heaters, toasters, and ovens to produce heat for cooking or warming up food. When an electric current flows through a wire, it generates heat due to the resistance of the wire. This heat can be used for various purposes.

Q.2. Explain how an electric bell works.

An electric bell contains a metal bell and an electromagnet. When an electric current flows through the electromagnet, it generates a magnetic field that attracts a metal armature. This causes the armature to strike the bell and produce a ringing sound. The current is controlled by a switch that turns it on and off.

Q.3. What is an electromagnet? How is it different from a permanent magnet?

An electromagnet is a type of magnet that is created by passing an electric current through a coil of wire. The coil generates a magnetic field that can attract or repel other objects. Unlike a permanent magnet, which always has a magnetic field, an electromagnet only has a magnetic field when there is a current flowing through it. This makes it useful for many applications where a magnetic field is needed temporarily.

Q.4. What is magnetic field? How is it related to the flow of electric current?

A magnetic field is a region around a magnet or a wire carrying an electric current where a magnetic force can be detected. The strength of the magnetic field is related to the flow of electric current through the wire. The direction of the magnetic field can be determined by using the right-hand rule, which states that if you point your thumb in the direction of the current flow, the direction of the magnetic field is given by the curl of your fingers.

Q.5. What are the different parts of a circuit diagram? Explain their functions.

A circuit diagram is a graphical representation of an electric circuit. It typically includes symbols for the various components of the circuit, such as resistors, capacitors, switches, and batteries. The diagram also shows the connections between the components and the direction of the current flow. The different parts of a circuit diagram are: the power source, which provides the energy for the circuit; the load, which uses the energy in the circuit to perform some work; and the conductors, which connect the various components of the circuit together. The switches are used to control the flow of current in the circuit.

Section C: Fill in the Blanks

Q.1. ____________ is the process of movement of substances in plants.

Transpiration is the process of movement of substances in plants. It involves the loss of water vapor from the leaves through tiny pores called stomata, which creates a negative pressure that pulls water and nutrients from the roots up through the stem and into the leaves.

Q.2. The ____________ system carries oxygen and nutrients to all parts of the body in animals.

The circulatory system carries oxygen and nutrients to all parts of the body in animals. It consists of the heart, blood vessels, and blood, and is responsible for maintaining homeostasis by regulating body temperature, pH, and other vital functions.

Q.3. An ____________ is a device that protects an electric circuit from damage caused by excess current.

An overload protector is a device that protects an electric circuit from damage caused by excess current. It works by interrupting the flow of current when it exceeds a certain threshold, preventing overheating and potential fires.

Q.4. ____________ is the process of generating a magnetic field around a conductor when an electric current flows through it.

Electromagnetic induction is the process of generating a magnetic field around a conductor when an electric current flows through it. This phenomenon was discovered by Michael Faraday in the 19th century and is the basis for many modern technologies, including generators, transformers, and electric motors.

Q.5. An ____________ is a device that produces sound when an electric current flows through it.

An electroacoustic transducer is a device that produces sound when an electric current flows through it. This includes speakers, microphones, and headphones, which convert electrical signals into acoustic waves or vice versa.

Section D: Match the column (In a Table)

1. Xylem: Highlight option B. Carries water and minerals in plants.
Xylem is a specialized tissue in plants that carries water and dissolved minerals from the roots to the rest of the plant. It is responsible for providing support and structure to the plant, as well as regulating water balance.
2. Phloem: Highlight option A. Carries food in plants.
Phloem is another specialized tissue in plants that carries dissolved sugars and other organic compounds from the leaves to other parts of the plant. It is responsible for providing energy to the plant and aiding in growth and development.
3. Blood vessels: Highlight option C. Carries oxygen and nutrients in animals.
Blood vessels are the network of tubes that carry blood throughout the body, delivering oxygen and nutrients to cells and removing waste products. They are responsible for regulating blood pressure and maintaining homeostasis in the body.
4. Electric Fuse: Highlight option D. Protects electric circuit from damage caused by excess current.

An electric fuse is a safety device that protects an electrical circuit from damage caused by excess current. When the current in the circuit exceeds a certain level, the fuse melts and breaks the circuit, preventing further damage.
5. Electromagnet: Highlight option E. Generates magnetic field around a conductor when electric current flows through it.
An electromagnet is a device that generates a magnetic field around a conductor when an electric current flows through it. It is used in a variety of applications, including motors, generators, and speakers. The strength of the magnetic field can be controlled by adjusting the current flowing through the conductor.

Section E: True False

True
Xylem is a type of tissue in plants that transports water and minerals from the roots to the rest of the plant.

Q.2. Phloem transports food in animals. (True/False)

True
Phloem is another type of tissue in plants that transports food (sugar) from the leaves to the rest of the plant.

Q.3. Heating effect of electric current is used in electric heaters. (True/False)

True
Electric heaters use the heating effect of electric current to convert electrical energy into heat energy.

Q.4. Magnetic effect of electric current is used in MRI machines.

True
MRI (Magnetic Resonance Imaging) machines use the magnetic effect of electric current to produce detailed images of the inside of the body.

Q.5. Electric bell is an example of an electromagnet.

True
An electric bell uses an electromagnet to create a magnetic field that attracts and releases a metal clapper to produce a ringing sound.