The unit of work is MCQ with Answer and Explanation
Question
Report Error
Discuss this Question (0)
Practice More Physics Questions
Question #1
Report Error
A fuse in an electrical circuit is designed to:
Correct Answer: Option A
Explanation:
Fuse is a safety device with a wire that melts when current exceeds rated value, breaking the circuit and preventing damage from overcurrent/short circuits. It operates on Joule heating (I²R). Option A is opposite; C describes capacitor; D describes rectifier. Memory tip: 'Fuse = sacrificial overcurrent protector'. This practical application question tests knowledge of electrical safety devices, frequently examined in competitive exams. Always link fuse rating to circuit requirements: fuse current rating slightly above normal operating current.
Fuse is a safety device with a wire that melts when current exceeds rated value, breaking the circuit and preventing damage from overcurrent/short circuits. It operates on Joule heating (I²R). Option A is opposite; C describes capacitor; D describes rectifier. Memory tip: 'Fuse = sacrificial overcurrent protector'. This practical application question tests knowledge of electrical safety devices, frequently examined in competitive exams. Always link fuse rating to circuit requirements: fuse current rating slightly above normal operating current.
Question #2
Report Error
The efficiency of a machine is defined as:
Question #3
Report Error
The universal law of gravitation states that the force between two masses is directly proportional to:
Correct Answer: Option B
Explanation:
Newton's law of gravitation: F = G·m₁m₂/r². Thus force is directly proportional to the product of the masses (m₁m₂) and inversely proportional to square of distance (r²). Option D incorrectly states 'directly proportional to square of distance' – it's inverse square. This fundamental law governs celestial mechanics. Memory tip: 'F ∝ m₁m₂ and F ∝ 1/r²'. Competitive exams often test precise wording of physical laws; distractors may reverse proportionality or misstate dependencies. Always recall the exact mathematical form.
Newton's law of gravitation: F = G·m₁m₂/r². Thus force is directly proportional to the product of the masses (m₁m₂) and inversely proportional to square of distance (r²). Option D incorrectly states 'directly proportional to square of distance' – it's inverse square. This fundamental law governs celestial mechanics. Memory tip: 'F ∝ m₁m₂ and F ∝ 1/r²'. Competitive exams often test precise wording of physical laws; distractors may reverse proportionality or misstate dependencies. Always recall the exact mathematical form.
No comments yet. Be the first to start the discussion!