Home
Class 12
MATHS
The length of time in hours that certain...

The length of time in hours that certain battery will last is inversely proportional to the length of time in years that the battery spends in storage. If the battery spends 3 years in storage, it will last 25 hours, so how long must the battery have been in storage if it will last 15 hours?

A

1.75 years

B

5 years

C

`41(2)/(3)` years

D

75 years

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • ARITHMETIC

    PRINCETON|Exercise QUICK QUIZ #8|3 Videos

  • ARITHMETIC

    PRINCETON|Exercise QUICK QUIZ #9|4 Videos

  • ARITHMETIC

    PRINCETON|Exercise QUICK QUIZ #6|3 Videos

  • ALGEBRA: CRACKING THE SYSTEM

    PRINCETON|Exercise Algebra Drill 2: Calculator-Permitted Section|6 Videos

  • FUN WITH FUNDAMENTALS

    PRINCETON|Exercise Fundamental Drill 2: Calculator- Permitted Section|6 Videos

Similar Questions

Explore conceptually related problems

The amount of time it takes to consume a buffalo carcass is inversely proportional to the number of vultures. IF it takes 12 vultures 3 day to consume a buffalo, how many fewer hours will it take there are 4 more vultures?

The height of the steam burst of certain geyser varies with the length of time since the previous steam burst. The longer the time since the last burst, the greater the height of the steam burst. If t is the time in hours since the previous steam burst and H is the height in meters of the steam burst, which of the following could express the relationship of t and H?

The rate of increase in the number of bacteria in a certain bacteria culture is proportional to the number present. Given the number triples in 5 hrs., find how many bacteria will be present after 10 hours. Also find the time necessary for the number of bacteria to be 10 times the number of initial present. [Given log_e3=1. 0986 ,\ e^(2. 1972)=9 ]

A 10 V storage battery of negligible internal resistance is connected across a 50Omega resistor. How much heat energy is produced in the resistor in 1 hour

A car has a fresh storage battery of emt 12 V and internal resistance 5.0 xx 10^(-2) Omega . If the starter moter draws a current of 90A, what is the terminal voltage of the battery when the starter is on? (b) After long use, the internal resistance of the storange battery increase to 500 Omega . What maximum current can be drawn from the battery? Assume the emt of the battery to remain unchanged. (c) If the discharged battery is changed by an external emf source, is the terminal voltage of the battery during changing greater of less than is emf 12 V ?

During the discharge of a lead storage battery, the density of sulphuric acid fell from 1.13 to 1.15 g/ ml^(−1) and sulphuric acid of the density of 1.3 g/ ml^(−1) is 40% by mass and that of the density of 1.15 g/ ml^(−1) is 20% by mass. The battery holds 3.5 litre of acid and the volume practically remained constant during the discharge. Calculate the no. of ampere hour for which the battery must have been used. The charging and discharging reactions are: Pb+SO_(4)^(-2)rarrPbSO_(4)+2e^(-) (charging) PbO_(2)+4H^(+)+SO_(4)^(2-)+2erarrPnSO_(4)+2H_(2)O (discharging)

A certain exam lasts a total of 4 hours. Each part of the exam required the same amount of time and 10 minute brekas are included between consecutive parts. If there is a total of 4 breaks during the 4 hours, what is the required time, in minutes, for each part of the test?

A small, circular ring is inside a larger loop that is connected to a battery and a switch as shown in Fig. 3.25. Use Lenz's law to find the direction of the current induced in the small ring (a) just after switch S is closed, (b) after S has been closed for a long time, ( c) just after S has been reopened after being closed for a long time. ltbr.

Electromagnetic brakes work on the principle of electromagnetic induction. If a metallic disc or a coil is rotating in a uniform magnetic field, it will experience a torque due to induced currents set up in the disc. According to Lenz's law, induced current is in a direction so as to oppose the rotation. Hence a retarding torque is produced. The rotating wheel of a vehicle is connected to a coil placed in a uniform emf is used to charge a battery. Thus kinetic enery of wheel is stored as chemical energy. The drawback of electromagnetic brake is that induced current or retarding torque is directly proportional to speed of rotation. The speed, therefore, decays exponentially and vehicle will take a long time to stop. Thus, mechanical brakes are used simultaneously. The advantage of electromagnetic brakes is that