ECAT Pre General Science Physics Chapter 12 MCQ Test With Answer

The unit of resistivity is

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

The relation between charge 'Q' and current 'I' is given by

• Q = I/t A
• Q = It B
• Q = I²t C
• Q = I²/t 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

If we increase the distance between two plates of the capacitor, the capacitance will

• Increase A
• Decrease B
• Remain same C
• First increase then decrease D

The graphical representation of ohm's law is

• hyperbola A
• straight line B
• ellipse C
• parabola D

Physicist George Simon ohm was a

• German physical A
• French physicist B
• Chinese physicist C
• Russian physicist 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

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

Calculate the amount of charge flowing in 2 minutes in a wire of resistance 10Ωwhen a potential difference of 20 V is applied between its ends

• 120 C A
• 240 C B
• 20 C C
• 4 C D

The unit of conductance is

• ohm A
• meter B
• mho C
• ohm-meter 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 electric intensity at infinite distance from the point charge will be

• Infinite A
• Positive B
• Zero C
• Negative D

The unit of intensity of electric field is

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

• 5μF A
• 10μF B
• 3μF C
• 6μF 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

Which one of the following has larger value of relative permitivity E_rat room temperature?

• Vaccum A
• Air B
• Glass C
• Water D

A piece of fuse wire melts when a current of 15 ampere flows through it. With this current. If it dissipates 22.5 W, the resistance of fuse wire will be

• Zero A
• 10Ω B
• 1Ω C
• 0.10Ω D

The resistance of the given conductor can be increased by

• Increasing the area A
• Changing resistivity B
• Decreasing the length C
• None of the above because change does not matter because in any case the volume remains the same D

Ohm is the unit of

• current A
• capacitance B
• energy C
• resistance D

In bringing an electron towards another electron, electrostatic potential energy of system

• Decreases A
• Increases B
• Remains uncharged C
• Becomes zero D

The SI unit of conductivity is

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

A capacitor is charged with a battery and then it is disconnected. A slab of dielectric is now inserted between the plates, then

• The charge in the plates reduces and potential difference increase A
• Potential difference between the plates increase, stored energy decreases and charge remains the same B
• Potential difference between the plates decreases and charge remains unchanged C
• None of the above D

Coulomb force, when any material medium is placed between two charges

• Increases A
• Decreases B
• Remain unchanged C
• None of these 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

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 point charge Q is placed at the mid-point of a line joining two charges. 4q and q. if the net force on charge q is zero. then Q must be equal to

• -q A
• +q B
• -2q C
• +4q 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

The SI unit of electric field intensity is

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