Q1: Who discovered that certain substances attract light objects when rubbed?
Ans: William Gilbert.
Q2: What is the SI unit of electric charge?
Ans: Coulomb (C).
Q3: According to Coulomb’s law, the electrostatic force between two charges is inversely proportional to the square of what quantity?
Ans: Distance between them.
Q4: What type of materials allow electricity to flow freely?
Ans: Conductors.
Q5: Why does adding salt to distilled water increase its conductivity?
Ans: Due to the presence of ions that facilitate current flow.
Q6: What is the relationship between current, charge, and time?
Ans: I = q/t.
Q7: Why is the frequency of direct current (DC) zero?
Ans: Because it flows in only one direction.
Q8: What is the frequency of AC in India?
Ans: 50 Hz.
Q9: What instrument is used to measure electric current?
Ans: Ammeter.
Q10: What is the formula for electric potential difference?
Ans: V = W/Q.
Q11: What happens to the resistance of a conductor when its length is doubled?
Ans: It doubles.
Q12: Which physical property of a material determines its resistance?
Ans: Resistivity (ρ).
Q13: Why are alloys preferred for heating devices?
Ans: They have higher resistivity and do not oxidize readily.
Q14: What is the formula for power in terms of voltage and current?
Ans: P = VI.
Q15: What is the commercial unit of electrical energy?
Ans: Kilowatt-hour (kWh).
Q16: Which effect of electric current is used in electric bulbs?
Ans: Heating effect.
Q17: Why are CFLs preferred over incandescent bulbs?
Ans: They reduce energy wastage.
Q18: Which device is used to protect household circuits from overloading?
Ans: Miniature Circuit Breaker (MCB).
Q19: What rule determines the direction of the magnetic field around a current-carrying conductor?
Ans: Right-hand thumb rule.
Q20: What is the principle behind the working of an electric motor?
Ans: A current-carrying coil placed in a magnetic field experiences a torque.
Q1: The SI unit of resistance is the ____.
Ans: Ohm (Ω)
Q2: The heating effect of electric current is explained by ____ law.
Ans: Joule’s
Q3: The total resistance in a series circuit is the ____ of individual resistances.
Ans: Sum
Q4: An electromagnet is formed when a solenoid is combined with a ____ core.
Ans: Soft iron
Q5: The strength of the magnetic field is maximum at the ____ of a magnet.
Ans: Poles
Q1: Statement: Air is a good conductor of electricity under normal conditions. (True/False?)
Ans: False (Air is an insulator unless ionized)
Q2: Statement: In a parallel circuit, the voltage across each resistor is different. (True/False?)
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?)
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?)
Ans: True
Q5: Statement: The direction of the induced current is determined using Fleming’s left-hand rule. (True/False?)
Ans: False (Fleming’s right-hand rule determines the direction of induced current)
34 videos|145 docs|32 tests
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1. What is the basic principle of electricity and magnetism? | ![]() |
2. How does a magnetic field affect electric current? | ![]() |
3. What are the applications of electromagnetism in daily life? | ![]() |
4. What is Ohm's Law and how does it relate to electricity? | ![]() |
5. What safety measures should be taken when working with electricity? | ![]() |