True-False

Question 11 Mark

State whether the following statement is true or false:
An electric motor converts mechanical energy into electrical energy.

Answer

False.
An electric motor converts electrical energy into mechanical energy.

View full question & answer→

Question 21 Mark

Force on a charge is maximum when the velocity and magnetic field are in perpendicular direction. [True/False]

Answer

True.Explanation:
The magnetic force is perpendicular to the velocity, so velocity changes in direction but not magnitude. The result is uniform circular motion. The component of the velocity perpendicular to the magnetic field produces a magnetic force perpendicular to both this velocity and the field.

View full question & answer→

Question 31 Mark

Magnetic field lines form closed loops. [True/False]

Answer

True.Explanation:
Magnetic lines of force form continuous closed loops because a magnet is always a dipole and as a result, the net magnetic flux of a magnet is always zero.

View full question & answer→

Question 41 Mark

$3.6 \times 10^6$ joules make 3.6kWh. [True/False]

Answer

True.Explanation:
1kWh = 1000Wh = 1000W × 3600 second = 3.6MWs = 3.6MJ.

View full question & answer→

Question 51 Mark

State whether the following statements are true or false:

A generator works on the principle of electromagnetic induction.
A motor works on the principle of electromagnetic induction.

Answer

True.
False.

View full question & answer→

Question 61 Mark

State whether the following statement is true or false:
The magnetic field inside a long circular coil carrying current will be parallel straight lines.

Answer

True.

View full question & answer→

Question 71 Mark

State whether the following statements are true or false,
The field at the centre of a long circular coil carrying current will be parallel straight lines.

Answer

True.

View full question & answer→

Question 81 Mark

As one senses a clockwise current on one side of a coil, it will behave as a south pole. [True/False]

Answer

True.Explanation:
The coil behave as a magnet with its front face acting as the south pole and its back face as the north pole.

View full question & answer→

Question 91 Mark

Fleming's left hand rule is used to find the direction of induced current. [True/False]

Answer

True.Explanation:
The direction of the induced magnetic field is sometimes remembered by Maxwell's corkscrew rule.

View full question & answer→

Question 101 Mark

State whether the following statements are true or false,
A wire with a green insulation is usually the live wire of an electric supply.

Answer

False.
Live wire has red insulation cover, whereas earth wire has green insulation colour in the domestic circuits.

View full question & answer→

Question 111 Mark

State whether the following statements are true or false,
An electric motor converts mechanical energy into electrical energy.

Answer

False.
An electric motor converts electrical energy into mechanical energy.

View full question & answer→

Question 121 Mark

State whether the following statement is true or false:
The axis of earth’s imaginary magnet and the geographical axis coincide with each other.

Answer

False.
The axis of earth’s imaginary magnet is inclined at an angle of 15° with the geographical axis.

View full question & answer→

Question 131 Mark

State whether the following statements are true or false,
An electric generator works on the principle of electromagnetic induction.

Answer

True.

View full question & answer→

Science True-False

Test yourself on this topic