Q1. What is the resistance of an ideal ammeter?
Q2. What is the resistance of an ideal
voltmeter?
Q3. Why should an ammeter have a high current carrying capacity?
Q4. Where is the magnetic field of a current element minimum?
Q5. Where is the magnetic field of a current element maximum?
Q6. Where is the magnetic field due to current through circular loop uniform?
Q7. What will be the path of a charged particle moving perpendicular to a uniform magnetic field?
Q8. What will be the path of a charged particle moving along the direction of a uniform magnetic field?
Q9. An ebonite rod is rubbed with wool or fur. What type of charges do they acquire?
Q10. A glass rod is rubbed with silk. What type of charges do they acquire?
Q11. Name any two basic properties of electric charges.
Q12. Two equal charges, distance x apart exert a force on one another. The change on one of the charges is doubled. What is the ratio of the distance between the two charges now and earlier if the force in the two cases is same?
Q13. On what conservation principle is the Kirchhoff's second law based?
Q14. Is the ratio of number of holes and number of electrons in an n-type extrinsic semiconductor more than, less than or equal to 1?
Q15. What is the conductivity of a semi-conductor at absolute zero?
Q16. An electric current is flowing due south along a power line. What is the direction of the magnetic field at a point above it?
Q17. An electric current is flowing due south along a power line. What is the direction of the magnetic field at a point below it?
Q18. Where is the magnetic field due to current loop through circular loop uniform?
Q19. A current is set up in a long copper pipe. Is there a magnetic field inside the pipe?
Q20. A current is set up in a long copper pipe. Is there a magnetic field outside the pipe?
Q21. How much is the energy gap in a conductor?
Q22. On which factors does the pole strength of a magnet depend?
Q23. What is the direction of magnetic dipole moment?
Q24. When is the magnetic flux crossing a given surface area held in a magnetic field maximum?
Q25. A metallic wire 1m in length is moving normally across a field of 0.1 T with a speed of 5m/s. Find the emf between the ends of the wire.
Q26. A wire kept along east-west direction is allowed to fall freely. Will an emf be induced across the ends of the wire?
Q27. What is the frequency of direct current?
Q28. What is the average value of a.c over a cycle and why?
Q29. State the phase relationship between the current flowing and the voltage applied in an a.c circuit for a pure resistor?
Q30. State the phase relationship between the current flowing and the voltage applied in an a.c circuit for a pure inductor?
Q31. What is displacement current due to?
Q32. Can we produce a pure electric or magnetic wave in space?
Q33. Name the basic source of electromagnetic waves.
Q34. How does the frequency of a beam of glass change when it goes from air into glass?
Q35. Two concave mirrors have the same focal length but the aperture of one is larger than that of the other. Which mirror forms the sharper image and why?
Q36. Which one has a greater critical angle- diamond or water?
Q37. An object is placed at the focus of concave lens. Where will its image be formed?
Q38. Can we observe interference maxima on the screen if the two slits are separated by less than a wavelength of light used?
Q39. Can radioactivity be controlled?
Q40. Under what condition does a p-n junction work as an open switch?
A3. Due to high current carrying capacity, an
ammeter is not damaged by excessive currents
A4. Magnetic field is minimum (zero) along the
axis of a current element
A5. Magnetic field is maximum in a plane passing
through the element and perpendicular to its axis
A6. At the centre of the current loop
A8. The charged particle will move along a
straight line path
A9. The ebonite rod acquires a negative charge
and fur or wool acquires an equal positive charge
A10. The glass rod
acquires positive charge and silk acquires an equal negative
charge
A11. Quantized,
additive and conserved
A12. F = (k * q * q )
/ (r * r) = (k * q * 2q)/(r' * r')
R'/r= square root of 2 : 1
A13. Kirchhoff's
second law is based on the law of conservation of energy.
A16. According to
right hand rule, the direction of field is towards west above the
wire
A17. According to
right hand rule, the direction of field is towards east below the
wire
A18. At the centre of
the current loop
A19. The magnetic
field is zero inside the pipe
A20. A finite magnetic
field exists outside the pipe
A22. The pole strength
of a magnet depends on 1) its area of cross-section 2) nature of
its material 3) its state of magnetization
A23. The direction of
magnetic dipole moment is from S-pole to N-pole of the magnet
A24. The flux is
maximum when the area is held perpendicular to the direction of
the magnetic field
A25. Emf = B * l * v=
0.1 * 1 * 5 = 0.5 V
A26. Yes, because the
horizontal component of earth's magnetic field is intercepted by
the wire
A27. The frequency of
d.c. is zero
A28. Zero, because
a.c. is positive during one half cycle and equally negative
during other half cycle
A29. In a pure
resistor, the current is in phase with the applied voltage
A30. In a pure
inductor, the current lags behind the voltage by a phase angle of
90 degree
A31. Displacement
current exists due to a time varying electric field or changing
electric flux
A33. An electric
dipole is a basic source of electromagnetic waves
A34. The frequency
remains unchanged
A35. The concave
mirror with smaller aperture forms the sharper image because it
is free from spherical aberration
A37. Image is formed
at infinity
A38. No, the fringe
width will become very large
A39. No, it cannot be
controlled by changing chemical conditions or the physical
conditions like temperature, pressure etc
