Tag: effect of electric current

Questions Related to effect of electric current

The essential requirements for a good heating element are _________________.

  1. High resistivity and low melting point

  2. High resistivity and high melting point

  3. Low resistivity and low melting point

  4. Low resistivity and high melting point


Correct Option: D
Explanation:

ESSENTIAL REQUIREMENTS OF GOOD HEATING ELEMENT High-specific resistance so that small length of wire may be required to provide given amount of heat. High-melting point so that it can withstand for high temperature, a small increase in temperature will not destroy the element.

If the current is flowing through a $10 \Omega$ resistor, then in which case the maximum heat will be generated?

  1. $5 \ ampere \ in \ 2 \ minutes$

  2. $4 \ ampere \ in \ 3 \ minutes$

  3. $3 \ ampere \ in \ 6\ minutes$

  4. $2 \ ampere \ in \ 5 \ minutes$


Correct Option: C
Explanation:

Heat generated $H = i^2 Rt$

(A) : $H _A = (5)^2 (10) (2\times 60) = 30 kJ$
(B) : $H _B = (4)^2 (10) (3\times 60) = 28.8 kJ$

(C) : $H _C = (3)^2 (10) (6\times 60) = 32.4 kJ$
(D) : $H _D = (2)^2 (10) (5\times 60) = 12 kJ$

Thus maximum heat is generated in case $C$.

What is CFL ?

  1. Compact Fluorescent Lamp

  2. Compact Fluorescent Lamina

  3. Complete Fluorescent Light

  4. Controlled Fluorescent Light


Correct Option: A
Explanation:

CFL is Compact Fluorescent Lamp.


It is widely used now days because of low pollution and low power consumption.
Answer-(A)

Name the effect of current responsible for the glow of the bulb in an electric circuit.

  1. Chemical

  2. Heating

  3. Magnetic

  4. Heating and Magnetic


Correct Option: B
Explanation:

The electric bulb has a filament called tungsten when electricity passes through this filament, it heats up and glows. 

This heat is generated due to the passage of electric current, the drift of electrons due to the current and the resistance it has.
Hence, the heating effect of electric current is responsible for the glow of the bulb in an electric circuit.