Physics - Study Mode
[#1096] What type of force acts on a car moving around a curve?
Correct Answer
(C) Centripetal force
Explanation
Solution: As a car makes a turn, the force of friction acting upon the turned wheels of the car provides centripetal force required for circular motion. As a bucket of water is tied to a string and spun in a circle, the tension force acting upon the bucket provides the centripetal force required for circular motion.
[#1097] Damp clothes are dried in spin dryers by the action of
Correct Answer
(B) Centrifugal forces
Explanation
Solution: The spin dryer is probably the most familiar centrifuge. The spin dryer of a washing machine removes excess water from the clothing by rotating at a high speed. The high speed of rotation creates a high centrifugal force for the water in the clothing which causes it to be pulled to the outside of the spinning portion of the washing machine and away from the clothes.
[#1098] Where do the electrical charges reside in a charged conductor?
Correct Answer
(D) Outer surface of the body
Explanation
Solution: The net electric charge of a conductor resides entirely on its surface.
[#1099] The strength of an electromagnet can be increased by
Correct Answer
(D) All of the above
Explanation
Solution: The strength of an electromagnet can be increased by increasing the length of the coiled wire, increasing current supply or increasing the number of turns.
[#1100] The unit of Planck's constant is
Correct Answer
(A) Js
Explanation
Solution: The dimension of Planck's constant is the product of energy multiplied by time, a quantity called action. Planck's constant is often defined, therefore, as the elementary quantum of action. Its value in metre-kilogram-second units is defined as exactly 6.62607015 × 10 -34 joule second.