36. A coiled wire becomes an electromagnet when _______ passes through it
(A) Heat
(B) Electric current
(C) Mercury
(D) Water current
Answer:
(B) Electric current
Explanation:
According to the principles of electromagnetism, when an electric current flows through a coiled wire (solenoid), it generates a concentrated magnetic field, effectively creating an electromagnet.
37. The solution used in voltaic cell is called:
(A) Electrolyte
(B) Eukaryotic
(C) Electrode
(D) Antidote
Answer:
(A) Electrolyte
Explanation:
An electrolyte is an electrically conductive solution containing free ions. In a voltaic (galvanic) cell, the electrodes must be submerged in an electrolyte solution to allow the flow of ions and generate electricity.
38. Which among the following allows the blood to circulate in human body?
(A) Expansion of wind pipe
(B) Contraction of heart muscle
(C) Diffusion
(D) Excretion
Answer:
(B) Contraction of heart muscle
Explanation:
The human heart acts as a biological pump. The rhythmic contraction of the heart muscle (myocardium) generates the necessary pressure to pump and circulate blood continuously throughout the cardiovascular system.
39. The SI unit of weight is:
(A) Ampere (A)
(B) Kelvin (K)
(C) Kilogram (kg)
(D) Newton (N)
Answer:
(D) Newton (N)
Explanation:
While mass is measured in kilograms (kg), weight is a force representing the gravitational pull exerted on an object. The SI unit for any force, including weight, is the Newton (N).
40. The pressure exerted by air around us is known as the:
(A) Atmospheric pressure
(B) Transformative pressure
(C) Magnetic force
(D) Magnetic field
Answer:
(A) Atmospheric pressure
Explanation:
Atmospheric pressure is the force per unit area exerted against a surface by the weight of the air molecules in the Earth’s atmosphere above it.
