Physics - Study Mode

[#141] Find the current (in A) when a charge of 500 Coulomb flows in 25 seconds.
Correct Answer

(B) 20

Explanation

Solution: Current = Charge/Time I = Q/t I = 500/25 I = 20 A.

[#142] What is the value of 1 kW = ?
Correct Answer

(A) 1000 W

Explanation

Solution: 1 kW = 1000 W.

[#143] The electric current in a metal wire is due to the flow of -
Correct Answer

(A) Electrons

Explanation

Solution: The electric current in a metal wire is due to the flow of electrons.

[#144] An electric fuse is based on
Correct Answer

(C) The heating effect of the current

Explanation

Solution: The electric fuse is based on the heating effect of the current. Electric fuse have low melting point so when high current flow through fuse wire it heated and melted and break down the electric circuit.

[#145] Metals are good conductors of electricity because
Correct Answer

(B) They contain free electrons

Explanation

Solution: Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions.