Electric Current(I)

Q.

Define electric current. What is the SI unit of electric current?

Q. What is quantization of charge ? Why a charge equals to $1\times {10}^{-19}$ is not likely to exist on a body ?

Q.

Are all physical quantities that have magnitude and direction vectors ? Give example to support your answer . When is a physical quantity called vector ?

Q. Which of the following devices is used to produce the electric current?

1. Electric motor
2. Galvanometer
3. Ammeter
4. Electric generator

Q.

What can cause a short circuit?

Q.

When two charged conducting bodies are brought together, then transfer of charge takes place till both acquire the same.............

Q.

A TV set picture tube shoots out a beam of electrons. The current due to this beam is 10mA. Then, the total number of electrons that will strike the TV screen every second are___

1. $6.25\times {10}^{16}$

2. $6.25\times {10}^{-16}$

3. $3.125\times {10}^{16}$

4. $5\times {10}^{16}$

Q.

A current of 0.5 A flows through a bulb for 2 minutes. Find the net charge that flows through the conductor.

1. 60 C

2. 5 C

3. 10 C

4. 600 C

Q.

‘n’ electrons flow through a cross section of a conductor in time t. If charge on an electron is e, write an expression for the current in the conductor.

1. ne/t

2. e/t

3. net

4. ne

Q.

A current of 1.5 A flows through a conductor for 2.0 s. What amount of charge passes through the conductor?

Q.

The path of a free electron in a metal is ___

1. Parabolic

2. Circular

3. Zig-Zag

4. Straight line

Q.

Name the wire which carries current to an electrical appliance.

Q.

How is the direction of flow of current between the two charged conductors determined by their potentials?

Q. Which of the following device can measure both the magnitude and direction of electric current in an electric circuit?

1. Voltmeter
2. Ammeter
3. Galvanometer
4. Potentiometer

Q.

Current in a circuit flows :

(a) in the direction from high potential to low potential

(b) in the direction from low potential to high potential

(c) in direction of flow of electrons

(d) in any direction.

Q.

There are two bodies A and B. 'A' has a positive charge whereas 'B' has no charge. When A and B are connected by a metallic wire, in what direction will the electrons flow?

1. Electrons flow in random directions and will effectively stay in their initial position.

2. Electrons won't move in any direction

3. Electrons flow in random directions and will effectively move from B to A

4. Electrons flow in random directions and will effectively move from A to B

Q. Ampere is the S.I. unit of .

1. voltage
2. current
3. charge

Q. Describe domestic electric circuits.

Q. Which of the following is equal to the electric current flowing in an electric circuit?

1. Speed with which a charge moves through a cross section area
2. The force that acts on a charge
3. Energy used to move a charge between two points
4. Amount of charge that moves through a cross section area in unit time

Q.

Which electrical current alters its direction in regular intervals of time?

1. Battery Current

2. Surface Current

3. Alternating Current

4. Direct Current

Q. A conductor carries a current of $0.5A$. How much charge would pass through a cross-section of the conductor in $20s$?

1. $20C$
2. $5C$
3. $10C$
4. $40C$

Q. Calculate the amount of work done required in moving $28\times {10}^{20}$ electrons across two points of a wire with a potential difference of $14V$.

Q.

According to the convention, the direction of flow of electric current is taken from positive terminal to the negative terminal of the battery, which is opposite to the flow of ___.

Q.

The potential difference applied to an X -ray tube is 5 k V and the current through it is 3.2 mA. Then the number of the electrons striking the target per second is

1. $1\times {10}^{16}$
   

2. $4\times {10}^{16}$

3. $2\times {10}^{16}$
   

4. $5\times {10}^{16}$
   

Q.

How long should a flow of ${10}^{19}$ electrons be maintained between two points A and B to have a constant current of 8 A flowing between them?

1. 5 s

2. 0.2 s

3. $1.6\times {10}^{19}$ s

4. $8\times {10}^{-19}$ s

Q.

The unit of current is :

(a) ampere (b) volt

(c) ohm (d) coulomb.

Q.

The time rate of flow of electric charge is the measure of electric___.

Q.

A current of 5 A flows through a circuit for 15 minutes. The amount of electric charge that flows through the circuit during this time equals __ C.

Q. What is shunt? Write its theory.

Q. ntA galvanometer of resistance G, is shunted by a resistance S .To keep the main current in the circuit unchanged , the resistance to be put in series with the galvanometer is?n ntExplain in detailn