Physics | Current

Practice Physics | Current on Bissoy — browse topics below and open any question.

Resistance and Electricity

Questions

KCL is based on the fact that

ক

There is a possibility for a node to store energy.

খ

There cannot be an accumulation of charge at a node.

গ

Charge accumulation is possible at node

ঘ

Charge accumulation may or may not be possible.

Relation between currents according to KCL is

ক

i1=i2=i3=i4=i5

খ

i1+i4+i3=i5+i2

গ

i1-i5=i2-i3-i4

ঘ

i1+i5=i2+i3+i4

Choose the incorrect statement from the following.

ক

Graphene loudspeakers consume much less power compared to other conventional commercial counterparts

খ

Graphene forms the thinnest coating for protecting metals against corrosion

গ

Graphene coatings are used to render water repelling properties to structures

ঘ

Graphene is incapable of being coated on photonic devices

What is the unit of resistance?

ক

ohm

খ

ohm-1

গ

ohm2

ঘ

ohm5

Which of the following statements are not true?

ক

Increasing pressure angle improves the tooth strength

খ

Contact duration is decreased with increase in pressure angle

গ

20⁰ pressure angle has quieter operation then 14.5⁰

ঘ

All of the statements are true

A closed switch has a resistance of

ক

Zero

খ

About 50 ohms

গ

About 500 ohms

ঘ

Infinity

Heat in a conductor is produced on the passage of electric current due to

ক

reactance

খ

capacitance

গ

impedance

ঘ

resistance

Dynamo is a device for converting

ক

Heat energy into electrical energy

খ

Mechanical energy into electrical energy

গ

Magnetic energy into electrical energy

ঘ

Chemical energy into electrical energy

Which one of the following is not a form of stored energy?

ক

Nuclear energy

খ

Potential energy

গ

Electrical energy

ঘ

Chemical energy

Which one of the following statements regarding Ohm's law is not correct?

ক

Ohm's law is an assumption that current through a conductor is always directly proportional to the potential difference applied to it

খ

A conducting device obeys Ohm's law when the resistance of a device is independent of magnitude and polarity of applied potential difference

গ

A conducting material obeys Ohm's law when the resistance of material is independent of the magnitude and direction of applied electric field

ঘ

All homogeneous materials obey Ohm's law irrespective of whether the field is within range or strong

Which of the following is not a conductor of electricity?

ক

Ceramic

খ

aluminium

গ

Tungsten

ঘ

Nickel

When the short circuit condition occurs, the current in the circuit

ক

becomes zero

খ

remains constant

গ

increases substantially

ঘ

keeps on changing randomly