(English Medium) ICSE Class 9 - CISCE Question Bank Solutions for Physics

Why are physical quantities expressed in the order of magnitude? Support your answer by an example.

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

Which sphere is at higher potential before electrical contact on the basis of convention?

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

Which sphere is at lower potential before electrical contact on the basis of convention?

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

In which direction conventional current flows?

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

In which direction electronic current flows?

There is a positively charged sphere A and negatively charged sphere B, such that they are brought in electrical contact by a copper wire.

What is the potential of the spheres after electrical contact?

What do you understand by the term electric potential?

Define electric potential in terms of energy spent.

State the unit of electric potential and define it.

What do you understand by the term quantity of electric charge?

State SI unit of electric charge and define it.

How many electrons constitute one unit electric charge in SI system?

What do you understand by the term electric current?

State and define the SI unit of electric current.

State the relation between electric current; the number of electrons moving in a circuit and time in seconds.

How electric current flows in solids?

How electric current flows in liquids?

How is potential difference related to work done and quantity of charge?

A charge of 8860 C flows through an electric circuit in 2 min and 40 s. Calculate the magnitude of current in a circuit.

Calculate the total number of electrons flowing through a circuit in 20 mins and 40 s, if a current of 40 μA flows through the circuit.
[1 e^– = 1.6 × 10^-19 C]