One Liner Questions Electricity and Magnetic Effect of Current - Science & Pedagogy

One Liner Questions

Q1: Who discovered that certain substances attract light objects when rubbed?

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Ans: William Gilbert.

Q2: What is the SI unit of electric charge?

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Ans: Coulomb (C).

Q3: According to Coulomb’s law, the electrostatic force between two charges is inversely proportional to the square of what quantity?

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Ans: Distance between them.

Q4: What type of materials allow electricity to flow freely?

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Ans: Conductors.

Q5: Why does adding salt to distilled water increase its conductivity?

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Ans: Due to the presence of ions that facilitate current flow.

Q6: What is the relationship between current, charge, and time?

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Ans: I = q/t.

Q7: Why is the frequency of direct current (DC) zero?

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Ans: Because it flows in only one direction.

Q8: What is the frequency of AC in India?

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Ans: 50 Hz.

Q9: What instrument is used to measure electric current?

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Ans: Ammeter.

Q10: What is the formula for electric potential difference?

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Ans: V = W/Q.

Q11: What happens to the resistance of a conductor when its length is doubled?

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Ans: It doubles.

Q12: Which physical property of a material determines its resistance?

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Ans: Resistivity (ρ).

Q13: Why are alloys preferred for heating devices?

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Ans: They have higher resistivity and do not oxidize readily.

Q14: What is the formula for power in terms of voltage and current?

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Ans: P = VI.

Q15: What is the commercial unit of electrical energy?

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Ans: Kilowatt-hour (kWh).

Q16: Which effect of electric current is used in electric bulbs?

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Ans: Heating effect.

Q17: Why are CFLs preferred over incandescent bulbs?

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Ans: They reduce energy wastage.

Q18: Which device is used to protect household circuits from overloading?

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Ans: Miniature Circuit Breaker (MCB).

Q19: What rule determines the direction of the magnetic field around a current-carrying conductor?

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Ans: Right-hand thumb rule.

Q20: What is the principle behind the working of an electric motor?

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Ans: A current-carrying coil placed in a magnetic field experiences a torque.

Fill in the Blanks

Q1: The SI unit of resistance is the ____.

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Ans: Ohm (Ω)

Q2: The heating effect of electric current is explained by ____ law.

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Ans: Joule’s

Q3: The total resistance in a series circuit is the ____ of individual resistances.

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Ans: Sum

Q4: An electromagnet is formed when a solenoid is combined with a ____ core.

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Ans: Soft iron

Q5: The strength of the magnetic field is maximum at the ____ of a magnet.

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Ans: Poles

Statement-Based Questions

Q1: Statement: Air is a good conductor of electricity under normal conditions. (True/False?)

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Ans: False (Air is an insulator unless ionized)

Q2: Statement: In a parallel circuit, the voltage across each resistor is different. (True/False?)

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Ans: False (Voltage remains the same across each resistor in a parallel circuit)

Q3: Statement: The resistance of a wire increases when its thickness increases. (True/False?)

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Ans: False (Resistance decreases as cross-sectional area increases)

Q4: Statement: Electric power is the rate of conversion of electrical energy into other forms. (True/False?)

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Ans: True

Q5: Statement: The direction of the induced current is determined using Fleming’s left-hand rule. (True/False?)

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Ans: False (Fleming’s right-hand rule determines the direction of induced current)