Question

1. Ohm's law states the relationship between -
a) electric current and resistance
(b) electric current and work
c) electric current and potential difference
(d) electric current and electric charge is used exclusively for the filaments of the bulbs.
(b) aluminium
a) copper
(c) silver
(d) tungsten
2. 3. The unit of resistivity is -
(b) ohm metre
(c) ohm - metre
(d) ohm per metre
4. An electric iron draws a current 4 A when connected to a 220 V mains. Its resistance must be
a) ohm
a) 1000 2
(b) 55 2
(c) 44 2
5. The magnetic field lines due to a straight wire carrying current are -
(b) circular (c) parabolic a) straight 6. Commercial electric motors do not use - (d) none of these (d) elliptical a) an electromagnet to rotate the armature large no. of turns of conducting wire in the current carrying coil c) a permanent magnet to rotate the armature b) effectively d) a soft iron core on which the coil is wound 7. Which of the following is not associated with Fleming's Right hand rule? (c) resistance (d) induced current (b) movement 8. The magnetic field lines inside a long current carrying solenoid are nearby - (b) circular (c) parabolic (d) elliptical 9. Which of the following observation helps us to determine that a chemical change has a) magnetic field a) straight taken place? a) change in temperature c) evolution of a gas (b) change in colour (d) all of these​

Answer 1

Answer:

1 (c) Electric current & potential difference

2(d) Tungsten (but not sure)

3(b) The unit of Resistivity is ohm meter

4 The resistance is 54 ohm

5 (b) circular

Explanation:

concentric circles whose centres lie on the wire.

6.(c) a permanent magnet

7.(d)induced current

8.

Answer 2

Answer:

Draw a line segment AB of length 5.4 cm , divide it into 4 equal parts.