Electric Current and Its Effects
Electric Current and its Effects
Questions
The combination of which of the following household appliances is not based on the heating effects of electric current?
- Immersion heater and electric geyser
- Electric iron and geyser
- Refrigerator and air conditioner
- Electric iron and toaster
- Toaster and hot plate
Which of the following devices does not use electrical batteries?
- TV remote control
- Torch
- Inverter
- Toy car
- Radio
The materials that allow electric current to flow are good conductors of electricity. Which of the following materials is/are not a good conductor of electricity?
- Metals
- Salt solutions
- Acid solutions
- Vacuum
- Alkaline solutions
Which of the following statements is/are false?
a. When the switch is in the ‘ON’ position, the circuit from the negative terminal of the battery to the positive terminal is complete.
b. An electric room heater contains a coil of wire called an element.
c. The amount of heat produced in a wire depends on its material, length and thickness.
- Only a
- Only a and b
- Only b
- Only b and c
- Only c
The thin wire in a bulb is called
- fuse
- circuit
- filament
- wire
- element
Which of the following statements is/are false?
a. An electric battery consists of only one cell.
b. Many devices use electric batteries.
c. Electric cells are always placed one after the other to create a battery.
- Only a
- Only a and b
- Only b
- Only b and c
- Only c
Which of the following elements is not used for making a resistance wire?
- Tungsten
- Manganin
- Constantan
- Copper
- Nichrome
Which of the following statements is/are incorrect?
a. Current does not flow if a circuit is complete.
b. An electric circuit is opened when the switch is in the ‘ON’ position.
c. A bulb will glow only when the electric circuit is open.
- a only
- b only
- c only
- b and c
- a, b and c
When electric current is passed through an electric bulb, which of the following types of energy are produced?
a. Heat energy
b. Sound energy
c. Light energy
- Only a and b
- Only b and c
- Only c
- Only a and c
- Only b
Which of the following cause(s) excessive currents in electrical circuit?
- Overload in circuit
- Direct touching of wires
- Insulation on the wires coming off due to wear and tear
- Connection of many devices to a single socket
- All of the above
Which of the following statements is/are correct?
a. Different types of fuse are used in different types of circuits.
b. These days, MCBs are used in place of fuses.
c. Any wire or strip of metal can be used in place of a fuse.
- only a and b
- only b and c
- only a and c
- a, b and c
- only a
Which of the following statements is/are correct?
a. In the symbol of electric cell, the longer line represents the positive terminal and the thicker, shorter line represents the negative terminal.
b. The heat wastage can be reduced by using CFL bulbs in place of electric bulbs.
c. The ISI mark on an electrical appliance ensures that the circuit has been checked and is working properly.
- a only
- b only
- c only
- a and b
- a, b and c
Which of the following are uses of electromagnets?
a. Cranes at the sea docks use electromagnets.
b. Doctors use them for picking up tiny magnetic materials that have fallen in the eye.
c. Doctors use electromagnets during ultrasonic treatments.
- only a and b
- only b and c
- only a and c
- a, b and c
- only a
Hans Christian Oersted was the first person to
- create a battery with cells
- observe the heating properties of electrical circuits
- observe the magnetic effect of electrical circuits
- create a circuit breaker
- observe that excessive currents in circuits burn wires
Which of the following statements is/are correct?
a. When electric current passes through a wire, it behaves like a magnet.
b. Even when the electric current is switched off, the wire will not lose its magnetism.
c. Electromagnets can be made very strong and can lift very heavy loads.
- only a and b
- only b and c
- only a and c
- a, b and c
- only b