Assertion and Reason Questions Chapter-3 Current Electricity
Assertion (A) and other labelled Reason (R). Select the correct answer to these
questions from the options as given below.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, but R is not the correct explanation of A.
C. A is true, but R is false.
D. A is false, but R is true.
1. Assertion (A): The unit of electric current is the ampere.
Reason (R): One ampere is defined as the flow of one coulomb of
charge per second.
2. Assertion (A): The direction of conventional current is opposite to the flow
of electrons.
Reason (R): Electrons are negatively charged particles.
3. Assertion (A): Ohm's law states that the current through a conductor is
directly proportional to the voltage across it.
Reason (R): This relationship holds true for all types of
materials.
4. Assertion (A): In a series circuit, the current remains constant throughout
all components.
Reason (R): The voltage across each component can vary in a series
circuit.
5. Assertion (A): In a parallel circuit, the total current is equal to the sum
of the currents through each branch.
Reason (R): The voltage across each branch in a parallel circuit
is the same.
6. Assertion (A): The resistance of a conductor increases with an increase in
temperature.
Reason (R): Increased temperature causes more frequent collisions
between charge carriers.
7. Assertion (A): A voltmeter is always connected in series with the circuit
elements.
Reason (R): A voltmeter measures the potential difference across
two points.
8. Assertion (A): An ammeter is used to measure current flowing through a
circuit.
Reason (R): An ammeter has a very high resistance to ensure
accurate measurements.
9. Assertion (A): The power consumed in an electrical circuit can be calculated
using P=IV.
Reason (R): P represents power, I is current, and V is
voltage.
10. Assertion (A): The total resistance in a series circuit is the sum of the
individual resistances.
Reason (R): In a series circuit, the current is the same through
all components.
11. Assertion (A): Kirchhoff's voltage law states that the sum of the potential
differences in any closed loop of a circuit is zero.
Reason (R): This is due to the conservation of energy principle in
electrical circuits.
12. Assertion (A): The current in a conductor is directly proportional to the
electric field applied across it.
Reason (R): This relationship is described by Ohm's law.
13. Assertion (A): The total resistance in a parallel circuit decreases with the
addition of more resistors.
Reason (R): Adding more paths for current allows more charge to
flow.
14. Assertion (A): A capacitor blocks direct current (DC) while allowing
alternating current (AC) to pass.
Reason (R): Capacitors store charge and only allow changes in
voltage to pass.
15. Assertion (A): Superconductors exhibit zero resistance below a certain
critical temperature.
Reason (R): This property is due to the alignment of electron
pairs in the material.
16. Assertion (A): The internal resistance of a battery affects its output
voltage.
Reason (R): Higher internal resistance results in greater voltage
drop when current flows.
17. Assertion (A): Resistance depends on the material, length, and
cross-sectional area of the conductor.
Reason (R): These factors affect the ability of the conductor to
allow current flow.
18. Assertion (A): The drift velocity of electrons in a conductor is very high.
Reason (R): Electrons collide frequently with the atoms of the
conductor.
19. Assertion (A): A resistor in an electric circuit can convert electrical
energy into heat energy.
Reason (R): The heat generated is proportional to the current
squared times resistance.
20. Assertion (A): In a circuit, the voltage across each resistor in series is
the same.
Reason (R): In a series circuit, the same current flows through
each resistor.
21. Assertion (A): The potential difference across a battery is constant
regardless of the current drawn.
Reason (R): This is due to the battery's internal resistance.
22. Assertion (A): The resistivity of a material is independent of its shape and
size.
Reason (R): Resistivity is an intrinsic property of a material.
23. Assertion (A): The electrical power in a circuit can be measured in watts.
Reason (R): One watt is defined as one joule per second.
24. Assertion (A): A battery can be modeled as a voltage source in series with a
resistor.
Reason (R): The internal resistance of the battery affects its
output voltage.
25. Assertion (A): The capacitance of a capacitor increases when the distance
between the plates is decreased.
Reason (R): Capacitance is directly proportional to the area of
the plates.
26. Assertion (A): An electrical circuit cannot operate without a complete path
for current.
Reason (R): Current requires a closed loop to flow.
27. Assertion (A): A fuse is used in electrical circuits to prevent excessive
current.
Reason (R): A fuse melts when the current exceeds its rating.
28. Assertion (A): In a resistive circuit, the current is not dependent on the
voltage.
Reason (R): The relationship between voltage and current is
defined by Ohm's law.
29. Assertion (A): The equivalent resistance in a parallel circuit can never
exceed the smallest resistance in the circuit.
Reason (R): Parallel resistors provide multiple paths for current
flow.
30. Assertion (A): The current through a capacitor increases with increasing
frequency of the applied voltage.
Reason (R): The capacitive reactance decreases with increasing
frequency.
31. Assertion (A): A short circuit occurs when a low-resistance connection forms
between two points in a circuit.
Reason (R): This connection allows excessive current to flow.
32. Assertion (A): The electric field inside a conductor in electrostatic
equilibrium is zero.
Reason (R): Charge carriers within the conductor redistribute to
cancel any electric field.
33. Assertion (A): The energy stored in a capacitor is given by the formula
U= \(\frac{1}{2}CV^{2}\) .
Reason (R): This formula is derived from the work done to charge
the capacitor.
34. Assertion (A): A circuit breaker automatically interrupts current flow to
protect the circuit.
Reason (R): Circuit breakers rely on fuses to function.
35. Assertion (A): The potential difference across a resistor is directly
proportional to the current flowing through it.
Reason (R): This relationship is defined by Ohm's law.
36. Assertion (A): The thermal effect of current is utilized in electric
heaters.
Reason (R): Electric heaters convert electrical energy into heat
energy.
37. Assertion (A): A potentiometer can be used to measure the potential
difference without drawing current from the circuit.
Reason (R): It operates based on the principle of null deflection.
38. Assertion (A): A battery connected in series with a resistor will have a
constant voltage across it during discharge.
Reason (R): The internal resistance of the battery does not change
during discharge.
39. Assertion (A): The effective resistance in a series circuit can be
calculated using \(\ {R_total} = {R_1} + {R_2} + {R_3} + ....\)
Reason (R): In series, the total current remains the same through
each resistor.
40. Assertion (A): Capacitors block DC while allowing AC to pass.
Reason (R): Capacitors store energy in the electric field.
41. Assertion (A): In a parallel circuit, the voltage across each resistor is
the same.
Reason (R): This property allows for individual operation of
resistors.
42. Assertion (A): Kirchhoff's voltage law states that the total voltage around
a closed circuit is zero.
Reason (R): This law is a consequence of the conservation of
energy.
43. Assertion (A): The internal resistance of a battery decreases as it
discharges.
Reason (R): This is due to the chemical changes occurring within
the battery.
44. Assertion (A): Supercapacitors have higher capacitance than traditional
capacitors.
Reason (R): This allows them to store more energy per unit volume.
45. Assertion (A): The current in a series circuit decreases when additional
resistors are added.
Reason (R): Adding resistors increases the total resistance of the
circuit.
46. Assertion (A): The total energy consumed in a circuit can be calculated
using the product of power and time.
Reason (R): Power is defined as energy consumed per unit time.
47. Assertion (A): The magnetic field around a current-carrying wire can be
detected using a compass.
Reason (R): The magnetic field is generated due to the movement of
electric charge.
48. Assertion (A): The voltage drop across a resistor is always less than the
supply voltage in a circuit.
Reason (R): Energy is dissipated in the form of heat in the
resistor.
49. Assertion (A): Ohm's law can be applied to both DC and AC circuits.
Reason (R): Ohm's law is applicable to linear components in
circuits.
50. Assertion (A): The power dissipated in a resistor is independent of the
resistor's temperature.
Reason (R): Temperature changes do not affect the resistance of
the material.