Default Title

Question (21)

QN001931

A lemon cell glows an LED faintly, but using two lemon cells together makes it brighter. This happens because

(A) combined cells supply more electrical energy
(B) lemons become magnetic
(C) resistance disappears completely
(D) LEDs start producing current

Correct Answer: A

Explanation:

Multiple cells increase the electrical output.

Link:

Report Error

Question (22)

QN001932

Why should the two electrodes in a lemon cell not touch each other directly?

(A) It may stop proper current flow through the circuit
(B) It increases electrolyte strength
(C) It permanently charges the lemon
(D) It cools the circuit instantly

Correct Answer: A

Explanation:

Direct contact may short circuit the cell.

Link:

Report Error

Question (23)

QN001933

Which factor is most important for producing electricity in a chemical cell?

(A) Presence of magnetic field only
(B) Suitable chemical reactions
(C) Colour of electrodes
(D) Shape of switch

Correct Answer: B

Explanation:

Electricity generation depends on chemical reactions.

Link:

Report Error

Question (24)

QN001934

A dry cell left unused for many years may fail to work because

(A) chemicals inside slowly deteriorate
(B) zinc becomes transparent
(C) wires become magnetic
(D) oxygen stops existing in air

Correct Answer: A

Explanation:

Chemicals lose effectiveness over time.

Link:

Report Error

Question (25)

QN001935

Which of the following best describes a battery?

(A) A group of connected cells
(B) A permanent magnet
(C) A heating coil
(D) A resistor only

Correct Answer: A

Explanation:

A battery consists of two or more connected cells.

Link:

Report Error

Question (26)

QN001936

Two identical bulbs are connected separately to one cell and two cells. The brighter bulb will be connected to

(A) one cell
(B) two cells
(C) both equally
(D) neither bulb glows

Correct Answer: B

Explanation:

Two cells provide more electrical energy to the bulb.

Link:

Report Error

Question (27)

QN001937

A battery-operated torch stops glowing suddenly. The most likely reason is that

(A) the cells are discharged
(B) the bulb becomes magnetic
(C) the switch produces oxygen
(D) resistance becomes absent

Correct Answer: A

Explanation:

Discharged cells cannot supply sufficient electrical energy.

Link:

Report Error

Question (28)

QN001938

Why are rechargeable batteries considered environmentally better than disposable cells?

(A) They can be reused many times
(B) They produce no electricity
(C) They contain no chemicals
(D) They never need charging

Correct Answer: A

Explanation:

Reusing batteries reduces waste generation.

Link:

Report Error

Question (29)

QN001939

A student observes white deposits around an old leaking cell. This indicates that

(A) chemicals inside have leaked out
(B) the cell became magnetic
(C) the bulb absorbed chemicals
(D) current increased suddenly

Correct Answer: A

Explanation:

White deposits are signs of chemical leakage.

Link:

Report Error

Question (30)

QN001940

In a chemical cell, the electrolyte mainly helps by

(A) blocking all current flow
(B) allowing movement of charges
(C) producing sound energy
(D) cooling the electrodes

Correct Answer: B

Explanation:

Electrolyte allows movement of ions and charges.

Link:

Report Error

Question (21)

A lemon cell glows an LED faintly, but using two lemon cells together makes it brighter. This happens because

Explanation:

Link:

Question (22)

Why should the two electrodes in a lemon cell not touch each other directly?

Explanation:

Link:

Question (23)

Which factor is most important for producing electricity in a chemical cell?

Explanation:

Link:

Question (24)

A dry cell left unused for many years may fail to work because

Explanation:

Link:

Question (25)

Which of the following best describes a battery?

Explanation:

Link:

Question (26)

Two identical bulbs are connected separately to one cell and two cells. The brighter bulb will be connected to

Explanation:

Link:

Question (27)

A battery-operated torch stops glowing suddenly. The most likely reason is that

Explanation:

Link:

Question (28)

Why are rechargeable batteries considered environmentally better than disposable cells?

Explanation:

Link:

Question (29)

A student observes white deposits around an old leaking cell. This indicates that

Explanation:

Link:

Question (30)

In a chemical cell, the electrolyte mainly helps by

Explanation:

Link:

Excel With Tutors

ExcelWithTutors

For Student

For Tutors

Learn

OUR POLICY