ECAT Pre Engineering Physics Chapter 12 MCQ Test With Answer

The electric lines of force are

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

The resistance of 20 cm long wire is 10Ω. When the length is changed to 40 cm. The new resistance is

• 10Ω A
• 20Ω B
• 30Ω C
• 40Ω D

The liquid which conduct current is known as

• heating effect A
• chemical energy B
• electrolyte C
• ohm's law D

A ten ohm electric heater operates on a 110 V line. Calculate the rate at which it develops heat in watts

• 1310 W A
• 670 W B
• 810 W C
• 1210 W D

In RC series circuit the time during which the capacitor acquires 0.63 times the equilibrium charge is called

• Time constant A
• Decay constant B
• None of these C
• All of above D

Two electric bulbs of 200 W and 100 W have same voltage. If R₁and R₂be their resistance respectively then

• R₁= 2R₂ A
• R₂= 2R₁ B
• R₂ = 4R₁ C
• R₁= 4R₂ D

A certain charge liberates 0.8 g of oxygen. The same charge will liberate. how many g of silver?

• 108 g A
• 10.8 g B
• 0.8 g C
• 108/0.8 g 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

Electron volt is the unit of.

• Potential difference A
• Energy B
• Resistance C
• Capacitance D

The concept of field theory was put forward by

• Franklin A
• Kepler B
• Oersted C
• Michael Faraday 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

For two resistance wires joined in parallel, the resultant resistance is 6/5 ohm. When one of the resistance wire breaks, the effective resistance becomes 2 ohm. The resistance of the broken wire is

• 3/5 ohm A
• 2 ohm B
• 6/5 ohm C
• 3 ohm D

Consider a spherical shell of metal at he centre of which a positive point charge is kept

• The electric filed is zero outside the shell A
• The electric field is zero everywhere B
• The electric field is zero in the region inside the shell C
• The electric field is non-zero in both regions outside and inside the shell D

• 5μF A
• 10μF B
• 3μF C
• 6μF D

If a 40 watt light bulb burns for 2 hours. how much heat is generated

• 288 x 10³J A
• 288 x 10⁸J B
• 288 x 10⁵J C
• 288 x 10⁶J 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

If 2.2 kilowatt power is transmitted through 1 10 ohm line at 22000 volt, the power loss in the form of heat will be

• 0.1 watt A
• 1 watt B
• 10 watt C
• 100 watt D

A (100 W , 200 W) bulb is connected to a 160 V power supply. The power consumption would be

• 64 W A
• 80 W B
• 100 W C
• 125 W D

The SI unit of electric field intensity is

• CN^-1 A
• NC^-1or Vm^-1 B
• JC^-1 C
• AV^-1 D

The unit of conductance is

• ohm A
• meter B
• mho C
• ohm-meter D

Ohm established a relation between

• voltage and resistance A
• voltage and charge B
• voltage and current C
• voltage resistance and charge D

Current provided by a battery is maximum when

• Internal resistance equal to external resistance A
• Internal resistance is greater than external resistance B
• Internal resistance is less then external resistance C
• None of these D

The dot product of electric field intensity E and vector area A is called

• Electric potential A
• Electric flux B
• Electric field C
• Magnetic field D

A wire is bent into a ring of radius R is given a charge q. The magnitude of the electrical field at the centre of the ring is

• Two A
• 1/2 B
• Zero C
• 3/2 D

Battery is charged in motor cars, which is based on

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

The minimum resistance that can be obtained by connecting 5 resistance of 1/4Ωeach is

• 4/5Ω A
• 5/4Ω B
• 20Ω C
• 0.05 Ω 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 unit of intensity of electric field is

• newton/coluomb A
• jule/coluomb B
• volt x metre C
• newton/metre D

The SI unit of conductivity is

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