ECAT Pre Engineering Physics Chapter 12 MCQ Test With Answer

• 5μF A
• 10μF B
• 3μF C
• 6μF D

Battery is charged in motor cars, which is based on

• Chemical effect A
• Magnetic effect B
• Electric effect C
• None D

The substances whose resistance decreases with the increase in temperature these substances have coefficient of

• positive temperature A
• negative temperature B
• absolute temperature C
• zero temperature D

The minimum charge on any object can not be less than

• 1.6 x 10^-19C A
• 3.2 x 10^-19C B
• 1.0 C C
• 4.8 x 10^-19C D

The conductivity of a superconductor is

• Infinite A
• Very large B
• Very small C
• Zero D

The electric field intensity at a point due to a point charge

• Falls off inversely as the distance A
• Falls off inversely as the square of distance B
• Remains unchanged with distance C
• Increase directly as square of distance D

The fractional change in resistance per kelvin is known as

• temperature coefficient A
• resistance coefficient B
• super temperature C
• critical temperature D

Electric flux is defined by the relation

• E.A. A
• E x A B
• E/A C
• none of these D

The electric field will be uniform

• Near a positive point charge A
• Near a negative point charge B
• Between two oppositely charged parallel metal plates C
• None of above D

Two conductors having the same type of charges are connected by a conducting wire. There would not be any amount of charges on them if

• They have the same potential A
• They have the same amount of charge B
• They have the same capacity C
• They have the same shape D

At any point on the right bisector of the line joining two equal and opposite charges

• At electric field is zero A
• The electric potential is zero B
• The electric potential decreases with increasing distance from the centre C
• The electric field is perpendicular to the line joining the charges D

A 50 volt battery is connected across 10 ohm resistor. The current is 4.5 A. The internal resistance of the battery is

• Zero A
• 0.5Ω B
• 1.1Ω C
• 5.0Ω D

Some charge is being given to a conductor. Then its potential

• Is maximum at surface A
• Is maximum at centre B
• Is remain same throughout the conductor C
• Is maximum somewhere between surface and centre D

When an electron is accelerated through a P.D. of an one volt, it will acquire energy equal to

• One joule A
• One erg B
• One electron volt C
• None of these D

A charge of 0.1 c accelerated through a potential difference of 1000V acquires kinetic energy

• 200 J A
• 100 J B
• 1000 J C
• 400 J D

Ohm's law states that

• The current through a resistor is directly proportional to the applied voltage A
• The voltage across a resistor is directly proportional to the current passing through it B
• Resistance is the constant of proportionality between the voltage and current C
• all of these D

The conventional current in a circuit is defined as " current which passes from a point at higher potential to a point at lower potential as if it represent a movement of

• negative charges A
• positive charges B
• protons C
• electrons D

Two point charge +3μC and +8μC repel each other with a force of 40 N. If a charge of -5μC is added to each of them, then the force between then will become

• -10 N A
• +10 N B
• +20 N C
• -20 N D

The powers of tow electric bulbs are 100 W and 200 W. Both of them are joined with 220 V mains. The ratio of resistances of their filaments will be

• 1 : 2 A
• 2 : 1 B
• 1 : 4 C
• 4 : 1 D

A one microfarad capacitor of a TV is subjected to 4000 V potential difference. The energy stored in capacitor is

• 8 J A
• 16 J B
• 4 x 10^-3J C
• 2 x 10^-3J D

The SI unit of conductivity is

• ohm-m A
• ohm^-1m^-1 B
• ohm-m^-1 C
• ohm^-1m D

Resistor is a device which convert electric energy to

• Heat energy A
• Chemical energy B
• Elastic energy C
• All of the above D

The colour sequence in a carbon resistor in red, brown, orange and silver. The resistance of the resistor is

• 21 x 10³+ 10% A
• 23 x 10¹+ 10% B
• 21 x 10³+ 5% C
• 12 x 10³+ 5% D

Two point charges A and B separated by a distance R attract each other with a force of 12 x 10^-3N. The force between A and B when the charges on them are doubled and distance is halved

• 1.92 N A
• 19.2 N B
• 12 N C
• 0.192 N D

A hollow insulated conduction sphere is given a positive charge of 10μC. What will be the electric field at the centre of the sphere if its radius is 2 meters?

• Zero A
• 5μC m^-2 B
• 20μC m^-2 C
• 8μC m^-2 D

What is the current is a 2 x 10⁶ohm resistor having a potential difference of 2 x 10³volts?

• 10^-1A A
• 10^-2A B
• 10^-4A C
• 1 mA D

A uniform resistance wire of Length L and diameter d has a resistance R. Another wire of same material has length, 4L and diameter 2d, the resistance will be

• 2 R A
• R B
• R/2 C
• R/4 D

The energy stored in a charge capacitor

• 1/2CV² A
• 1/2C²V B
• 1/2C/V² C
• None of these D

Magnetic effect at a point caused due to flow a current depend upon the

• Quantity of current A
• Distance from current B
• Both the quantity of current and distance from current element C
• None of the all D

In a voltmeter the conduction takes place due to

• Electrons only A
• Holes only B
• Electrons and holes C
• Electrons and ions D