Science [1 Mark Questions]

What is the SI unit of (i) electric energy, and(ii) electric power?

In which direction does conventional current flow around a circuit?

Will current flow more easily through a thick wire or a thin wire of the same material when connected to the same source? Give reason for your answer.

Name a device which helps to maintain potential difference across a conductor (say, a bulb).

Which device is used to measure p.d.?

Which of the following equation shows the correct relationship between electrical units?
1A = 1C/ s or 1C = 1A/ s.

Which among iron and mercury is a better conductor of electricity?

Explain why, filament type electric bulbs are not power efficient.

Write down the formula for the heat produced when a current I is passed through a resistor R for time.

State the relation between potential difference, work done and charge moved.

Are the lights in your house wired in series?

State the factors on which the strength of electric current flowing in a given conductor depends.

Two exactly similar heating resistances are connected (i) in series, and (ii) in parallel, in two different circuits, one by one. If the same current is passed through both the combinations, is more heat obtained per minute when they are connected in series or when they are connected in parallel? Give reason for your answer.

What happens to the other bulbs in a parallel circuit if one bulb blows off?

By what other name is the unit joule/ coulomb called?

What do the following symbols mean in circuit diagrams?

Name the quantity whose unit is (i) kilowatt, and(ii) kilowatt-hour.

Christmas tree lamps are usually wired in series. What happens if one lamp breaks?

How should the two resistances of 2 ohms each be connencted so as to produce an equivalent resistance of 1 ohm?

How can you change the brightness of the lamps?

Write down the formula which states the relation between potential difference, current and resistance.

A potential difference of 20 volts is applied across the ends of a resistance of 5 ohms. What current will flow in the resistance?

What do you understand by the term “potential difference”?

Keeping the potential difference constant, the resistance of a circuit is halved. By how much does the current change?

Which one has a higher electrical resistance: a 100 watt bulb or a 60 watt bulb?

What is the flow of charge called?

Which effect of current is utilised in the working of an electric fuse?

Draw a circuit diagram showing two lamps, one cell and a switch connected in series.

Which electric heating devices in your home do you think have resistors which control the flow of electricity?

How many milliamperes are there in 1 ampere?

What is the unit of electric charge?

What is the meaning of the symbol kWh? Which quantity does it represent?

Which has less electrical resistance : a thin wire or a thick wire (of the same length and same material)?

Draw a circuit diagram showing two electric lamps connected in parallel together with a cell and a switch that works both lamps. Mark an on your diagram to show where an ammeter should be placed to measure the current.

If 20C of charge pass a point in a circuit in 1s, what current is flowing?

One coulomb of charge flows through any cross-section of a conductor in 1 second. What is the current flowing through the conductor?

How does the resistance of a pure metal change if its temperature decreases?

An electrician has wired a house in such a way that if a lamp gets fused in one room of the house, all the lamps in other rooms of the house stop working. What is the defect in the wiring?

The graph between V and 1 for a conductor is a straight line passing through the origin.
Which law is illustrated by such a graph?
What should remain constant in a statement of this law?

How much work is done in moving a charge of 2C across two points having a potential difference of 12V?

Why do electricians wear rubber hand gloves while working with electricity?

State two factors on which the electrical energy consumed by an electrical appliance depends.

Which quantity has the unit of watt?

Name the commercial unit of electric energy.

How do you think the brightness of two lamps arranged in parallel compares with the brightness of two lamps arranged in series (both arrangements having one cell)?

What happens to the other bulbs in a series circuit if one bulb blows off?

Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:

1. For decorating a hotel building from outside?
2. For lighting inside the rooms of the hotel?

State the SI unit of resistivity.

Define one coulomb charge.

Write down the formula which relates electric charge, time and electric current.