Advertisements
Advertisements
Question
Find the odd one out.
Options
Loudspeaker
Bar magnet/magnet
Electric motor
Microphone
Solution
Bar magnet/magnet
Explanation:
A loudspeaker, microphone and electric motor are electrical devices, whereas a bar magnet/magnet is a natural or artificial substance that is not an electrical device. Therefore, the bar magnet/magnet is the odd one out.
RELATED QUESTIONS
Define the unit of current.
Calculate the number of electrons constituting one coulomb of charge.
Which of the following units could be used to measure electric charge?
(a) ampere
(b) joule
(c) volt
(d) coulomb
The atoms of copper contain electrons and the atoms of rubber also contain electrons. Then why does copper conduct electricity but rubber does not conduct electricity?
In 10 s, charge of 25 C leaves a battery, and 200 J of energy are delivered to an outside circuit a result.
What is the p.d. across the battery?
A battery and three lamps are connected as shown:
Which of the following statements about the currents at X, Y and Z is correct?
(a) The current at Z is greater than that at Y.
(b) The current at Y is greater than that at Z.
(c) The current at X equals the current at Y.
(d) The current at X equals the current at Z.
How does the heat H produced by a current passing through a fixed resistance wire depend on magnitude of current I?
If the current passing through a conductor is doubled, what will be the change in heat produced
The following circuit diagram shows three resistors 2 Ω, 4 Ω and R Ω connected to a battery of e.m.f 2V and internal resistance 3 Ω. If the main current of 0.25 A flows through the circuit, find:
- the p.d. across the 4 Ω resistors,
- the p.d. across the internal resistance of the cell,
- the p.d. across the R Ω or 2 Ω resistors, and
- the value of R.
Tick(✓) the correct choice in the following:
24 watt, 12 volt head lamp is fully lit by connecting it to a 12 volt
battery. The working resistance of the lamp is
Name the principle on which a transformer works.
My mother was operating washing machine on Sunday morning. Suddenly, she saw a spark coming out of the electric board and the electric current in the house failed. An electrician was called to look into the matter. What should he have noticed.
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
State expression for Cells connected in series.
How should the electric lamps in a building be connected?
Which of the following represents voltage?
What is the SI unit for the current?
