Q1. What is meant by a magnetic field?
Q2. How is the direction of magnetic field at a point determined?
Q3. Why are magnetic field lines closed curves?
Q4. Mention the shape of the magnetic field lines around a current-carrying straight conductor.
Q5. What type of core used to make an electromagnet?
Q6. Name the rule which gives the direction of induced current in a conductor.
Q7. State the rule which is used to find the direction of induced current.
Q8. How can it be shown that a magnetic field exists around a wire through which a direct current is passing?
Q9. In a domestic electric circuit, mention the potential difference between live wire and neutral wire and frequency of AC?
Q10. What is the advantage of the earth wire connection in domestic electrical circuits?
Q11. Which is the most important safety method used for protecting home appliances from short-circuiting or overloading?
Q12. List two sources of magnetic fields.
Q13. Define the term ‘induced current’.
Q14. When a current-carrying conductor is kept in a magnetic field, state the position when maximum force acts on it.
Q15. State the conclusions that can be drawn from the observation that a current-carrying wire deflects a magnetic needle placed near it.
Q16. Mention the angle between a current-carrying conductor and magnetic field for which the force experienced by this current-carrying conductor placed in magnetic field is largest.
Q17. Suggest one way of discriminating a wire carrying current from a wire carrying no current.
Q18. Name any two sources of direct current.
Q19. Mention the advantage of A.C. over D.C. for long-distance transmission.
Q20. List anyone point of difference between A.C. and DC.
Q21. What is Short Circuit?
Q22. Mention the name of three colours of the wires used in household wiring.
Q23. In which wire in an AC housing circuit, is the switch introduced to operate the light?
Q24. Why is an alternating current considered to be advantageous over direct current for long-range transmission of electric energy?
Direction (Q No. 25-29)In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as
(a) If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(c) If Assertion is true but Reason is false.
(d) If Assertion is false, but Reason is true.
(e) If Assertion and Reason both are false.
Q25. Assertion: A current-carrying conductor experiences a force in a magnetic field.
Reason: The force acting on a current-carrying conductor in a magnetic field is due to interaction between magnetic field produced by the current-carrying conductor and external magnetic field in which the conductor is placed.
Q26. Assertion: Electric Motor converts Electric Energy into mechanical Energy.
Reason: Electric motor is based on the principle of Flemings right-hand rule.
Q27. Assertion: Magnetic field lines do not intersect each other.
Reason: There cannot to two direction of the magnetic field at a point.
Q28. Assertion: The principle of Electromagnetic Induction was discovered by Michael Faraday.
Reason: The principle is used only in DC generators.
Q29. Assertion: Magnetic field can be created using a solenoid.
Reason: The strength of the magnetic field will depend on the number of turns of the solenoid.
Q30. The most important safety method used for protecting home appliances from short-circuiting or overloading is
(b) use of fuse
(c) use of stabilizers
(d) use of electric meter
Q31. The essential difference between AC generator and DC generator is that
(a) AC generator has electromagnet while DC generator has permanent magnet
(b) DC generator generates higher voltage
(c) AC generator generates higher voltage
(d) AC generator has slip rings while DC generator has commutator
Q32. The phenomenon of electromagnetic induction is
(a) the process of charging a body
(b) the process of generating magnetic field due to current passing through coil
(c) the process of producing induced current in a coil due to relative motion between a magnet and the coil
(d) the process of rotating a coil of an electric motor
Q33. Which of the following property of a proton can change while it moves freely in a magnetic field?