ECAT Pre Engineering Physics Chapter 12 MCQ Test With Answer

An alpha particle is accelerated through a potential difference of 10⁶volt. Its kinetic energy will be

• 1 MeV A
• 2 MeV B
• 4 MeV C
• 8 MeV D

The SI unit of electric flux is

• Weber A
• Nm²C^-1 B
• NmC^-1 C
• Nm^-2C D

A point charge A of charge +4μC and another B of charge -1μC are placed in air at a distance 1 m apart. Then the distance of the point on the line joining the charge B, where the resultant electric field is zero, is (in m)

• 2 A
• 1 B
• 0.5 C
• 1.5 D

A 60 W bulb operates on 220 V supply. The current flowing through the bulb is

• 11/3 A A
• 3 A B
• 3/11 A C
• 6 D

Electric flux is defined by the relation

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

If the resistance of 2 ohm and 4 ohm are connected in parallel, the equivalent resistance will be

• 6 ohm A
• 4 ohm B
• zero ohm C
• 1.33 ohm D

In a voltmeter the conduction takes place due to

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

The ohm's is defined as

• 1 ampere / 1 volts A
• 1 coulomb / 1 volt B
• 1 volt / 1 ampere C
• 1 volt / 1 coulomb D

A capacitor of capacity 1μF is charged to 1 KV. The energy stored in J

• 5 A
• 0.5 B
• 0.005 C
• 50 D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

The electric lines of force are

• Imaginary A
• Physically existing everywhere B
• Physically existing near the charge C
• All of the above D

The energy required to charge a capacitor of 5μF by connecting D.C. source of 20 KV is

• 10 KJ A
• 5 KJ B
• 2 KJ C
• 1 KJ 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

The ratio of the gravitational force F_gto the electrostatic force F_ebetween two electrons at the same distance apart is approximately

• 9.8 A
• 24 x 10¹⁹ B
• 24 x 10⁴² C
• 24 x 10^-44 D

If the two charges in Coulomb's law have double distance between them, then electric force

• Becomes two-fold A
• Becomes four-fold B
• Remains the same C
• None of these 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

When three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

• 180 watt A
• 10 watt B
• 20 watt C
• 60 watt D

A parallel plate capacitor is first charged and then a dielectric slab is introduced between the plates. The quantity that remains unchanged is

• Charge Q A
• Potential V B
• Capacity C
• Energy U D

Resistance of a conductor is increased, the currant will

• Decrease A
• Increase B
• Remain the same C
• None of these D

When a dielectric material is introduced between the plates of a charged condenser the electric field between the plates

• Decreases A
• Increases B
• No change C
• May increase or decresase D

The unit of resistivity is

• ohm A
• ohm-m² B
• ohm-meter C
• ohm-m^-1 D

The material in the form of wire or rod or plate which leads the current into or cut of the electrolyte is known as

• voltmeters A
• resistance B
• electrode C
• current D

A metal plate of thickness half the separation between the capacitor plates of capacitance C is inserted. The new capacitance is

• C A
• C/2 B
• Zero C
• 2C D

The electrode connected with the positive terminal of the current source is called

• cathode A
• anode B
• electrolyte C
• position D

One electron volt is equal to

• 1.6 x 1019eV A
• 6.25 x 1018 eV B
• 1.6 x 1018 eV C
• 6.25 x 1019eV 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

The relation V = IR represents

• Ampere law A
• Faraday's law B
• Ohm's law C
• Len's law 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

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

The SI unit of conductivity is

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