Choose Appropriate Alternative
- The direction of magnetic field lines in the region outside the bar magnet is...
[A] from the N pole towards the S pole of the magnet. [B] from the S pole towards the N pole of the magnet. [C] in the direction coming out from both the poles of the magnet. [D] in the direction entering both the poles of the magnet.
- Which of the following statements is false?
[A] The direction of magnetic field lines is from N to S. [B] In the region where magnetic field lines are at a close distance from one another, there will be a strong magnetic field. [C] The magnetic field lines form closed loops. [D] The magnetic field lines can cross one another.
- By which instrument can the presence of magnetic field be determined?
[A] Voltmeter [B] Ammeter [C] Galvanometer [D] Magnetic needle
- Who was the first to observe the magnetic effect of electric current?
[A] Faraday [B] Oersted [C] Volta [D] Ampere
- With the help of which law can the direction of a magnetic field decided?
[A] Faraday's law [B] Fleming's right hand rule [C] Right hand thumb rule [D] Fleming's left hand rule
- According to the Right hand thumb rule, direction of what is indicated by the thumb?
[A] Electric current [B] Magnetic field [C] Magnetic force [D] Motion of conductor
- The magnetic field produced in a straight conducting wire on passing current through it is...
[A] in the direction of current [B] in the direction opposite to the current [C] circular around the wire [D] in the direction parallel to the wire
- What is the type of field line of a magnetic field passing through the centre of current carrying circular ring?
[A] Circular [B] Straight line [C] Ellipse [D] Magnetic field is zero at centre.
- Which of the following has magnetic field like that of a bar magnet?
[A] Current carrying wire [B] Current carrying ring [C] Current carrying solenoid [D] Current carrying rectangular loop
- Who gave the principle of electromagnetic induction?
[A] Faraday [B] Oersted [C] Volta [D] Ampere
- Which is the direction of magnetic force acting on a current carrying wire placed in a magnetic field?
[A] along magnetic field [B] along the electric current [C] perpendicular to magnetic field [D] opposite to magnetic field
- How is a current carrying wire placed in a magnetic field so that magnetic field does not act on it?
[A] Parallel to the magnetic field [B] Perpendicular to the magnetic field [C] Making angle of 40° with magnetic field [D] Can be arranged any way.
- In which of the following cases, the induced current in the loop will not be obtained?
[A] The loop is moved in the direction of the magnet. [B] The magnet is moved in the direction of the loop. [C] The loop and the magnet are moved in opposite direction with same speed. [D] The loop and the magnet are moved in one direction with same speed.
- Which instrument is used for converting electrical energy into mechanical energy?
[A] Electric generator [B] Electric motor [C] Electric iron [D] Electric oven
- On which principle does the electric generator work?
[A] Electrical energy is converted to mechanical energy. [B] Electrical energy is converted to thermal energy. [C] Mechanical energy is converted to electrical energy. [D] Electrical energy is converted to light energy.
- The magnitude of AC voltage used in India is _____ and the frequency is _____.
[A] 110V, 60Hz [B] 110V, 50Hz [C] 220V, 50Hz [D] 220V, 60Hz
- Which coloured insulation cover is used for earthing wire?
[A] Red [B] Black [C] Green [D] Can be of any colour
- Which type of current is obtained from a battery?
[A] AC [B] DC [C] Both AC and DC [D] Depends on type of battery
- Which of the following instruments is used to know the presence of electric current?
[A] Fuse [B] Galvanometer [C] Voltmeter [D] Magnetic needle
- A fuse wire is...
[A] a conductor [B] an insulator [C] a semi-conductor [D] made of any material
- ______ is the rule used to know the direction of the induced current in the circuit.
[A] Fleming's left hand rule [B] Fleming's right hand rule [C] Right hand thumb rule [D] Ampere's rule
- How many times does an Alternating current (AC) with frequency 50Hz change its direction?
[A] 25 [B] 50 [C] 100 [D] 200
- At the centre of which of the following four circular rings the magnetic field is the strongest for equal magnitude of current?
[A] Figure A [B] Figure B [C] Figure C [D] Figure D
- The magnetism of magnets is maximum...
[A] at poles [B] at the centre [C] at the axis [D] everywhere in the magnet
- Within a bar magnet, the magnetic field lines are...
[A] from N to S [B] from S to N [C] absent [D] in both directions
- The strength of magnetic field produced in a current carrying straight conductor is...
[A] directly proportional to the distance from the wire [B] directly proportional to the magnitude of the current in wire [C] inversely proportional to the magnitude of the current in wire [D] independent of the magnitude of the current in wire
- The magnetic field inside a solenoid is...
[A] strong at N pole and weak at S pole [B] strong at S pole and weak at N pole [C] uniform throughout [D] zero
- What is not true?
[A] A solenoid is an electromagnet. [B] A solenoid is a temporary magnet. [C] A solenoid is a permanent magnet. [D] A solenoid is like a bar magnet.
- A fuse wire is generally made of...
[A] copper [B] aluminium [C] alloy of lead and tin [D] alloy of copper and lead
- In our domestic electric supply, we use following three colours of insulation cover on wires:
[A] Red, blue, green [B] Red, yellow, blue [C] Black, green, yellow [D] Red, black, green
- The current passing through two separate lines (circuits) of our houses is _____ A and _____ A.
[A] 5, 10 [B] 5, 15 [C] 10, 15 [D] 2, 5
- Which of the following is not a permanent magnet?
[A] Magnetic needle [B] Bar magnet [C] Electromagnet [D] Horse-shoe magnet
- The force experienced by a current carrying wire placed in a magnetic field will be maximum when it is...
[A] at an angle of 45° to the magnetic field [B] at right angle to the magnetic field [C] parallel to the magnetic field [D] anti-parallel to the magnetic field
- A magnetic field will not exert force on...
[A] a bar magnet [B] a stationary electric charge [C] an electromagnet [D] an electric charge moving perpendicularly to it
- On which of the following does the electromotive force not depend?
[A] The relative motion of the coil and magnet [B] Number of turns [C] Rate of change of flux linked with the coil[D] Material of the coil
- During the situation of short-circuit, the current in the circuit...
[A] reduces to zero [B] increases greatly [C] does not change [D] oscillates
- If many appliances are connected in a circuit, _____ may occur.
[A] short-circuit [B] long-circuit [C] over loading [D] explosion
- At the centre of which of the following four circular rings the magnetic field is the strongest for equal magnitude of current?
[A] Loop 1 [B] Loop 2 [C] Loop 3 [D] Loop 4
- Match the following in Part A with appropriate alternative in Part B.
[A] 1-b, 2-c, 3-d, 4-a [B] 1-c, 2-d, 3-b, 4-a [C] 1-a, 2-d, 3-b, 4-c [D] 1-a, 2-c, 3-d, 4-b
- What is the potential difference of the current flowing in the insulated wires in America?
[A] 220 V [B] 100 V [C] 110 V [D] 60 V
- _____ current line is connected to the air-conditioning machine.
[A] 20 A [B] 15 A [C] 10 A [D] 5 A
- If the current flowing through each turn of a solenoid is in the same direction, the magnetic field produced by n turns will be ____ with the magnetic field due to each turn.
[A] added [B] subtracted [C] multiplied [D] divided
- The magnitude of the induced current due to the relative motion of coil and a magnet does not depend on...
[A] speed of the relative motion [B] number of turns of coil [C] resistivity of wire of coil [D] pole strength of the magnet
- Which of the following statements is not suitable with reference to Direct Current(DC)?
[A] Electric current flows always from positive pole to negative pole. [B] The value of electric current is always constant with time. [C] Its production is cheap [D] More energy is wasted in its conduction
[A][B][C][D]
ANSWERS
(1) A (2) D (3) D (4) B (5) C (6) D (7) C (8) B (9) C (10) A (11) C (12) A (13) D (14) B (15) C (16) C (17) C (18) B (19) B (20) A (21) B (22) C (23) A (24) A (25) B (26) B (27) C (28) C (29) C (30) D (31) B (32) C (33) B (34) B (35) D (36) B (37) C (38) D (39) D (40) C (41) B (42) C (43) C (44) C (45)