题干

如图所示,将标有“12V 6W”的灯泡L1和“6V 6W”的灯泡L2并联后,接在6V的电源上(设灯丝电阻不变),则(  )

A:两灯的实际功率之和等于12W

B:两灯的实际功率之和大于12W

C:灯泡L1比灯泡L2

D:灯泡L2比灯泡L1

上一题 下一题 0.0难度 选择题 更新时间:2019-03-19 11:38:52

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D

同类题1

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    Getting older is a natural part of life. Changes as you get older are usually gradual. Certain physical changes are common. How fast your body can burn calories slows over time, which means that your body needs less food energy than before.

    How much and how well you sleep will likely change. Most people start needing reading glasses around forty, and many have some hearing loss later in life. Starting in your fifties, bone aging increase. How you feel as you get older depends on many things, including what health problems run in your family and the choices you make.

    If your family members have diseases or chronic (慢性的) health problems like high blood pressure, then you may have a greater chance of having those problems yourself. But it doesn't mean you will definitely have the same problems. Actually, the lifestyle choices you make can help reduce your chances of getting illness that run in your family. And even if you do get a family illness, choosing to be physically active, to eat healthy foods, and to learn how to deal with stress can keep the illness from destroying your ability to enjoy your golden years.

    What do you need to do to feel your best as you age? One of the most important things you can do for your health at any age is to be physically active. Physical activity keeps your body strong, and it helps with how you feel. People who stay active are less likely to get depressed.

    Your mental and emotional health is also important. Protect or improve your emotional health by staying in touch with friends, family, and the community. People who feel connected to others are more likely to feel happy than those who do not.

同类题3

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    The booking notes of the play “Sherlock”

    Price: $10

    BOOKING

    There are four easy ways to book seats for the performance:

    in person

    The Box Office is open from Monday to Saturday, 10 am—8pm

    by telephone

    Ring 01324976 to reserve your tickets or to pay by credit card (Visa and MasterCard).

    by post

    Simply complete the booking form and return it to Box Office.

    --online

    Complete the online booking form at www.Satanfiedtheatre.com.

    DISCOUNTS:

    Saver: $2 off any seat booked any time in advance for performances from Monday to Thursday. Saver s are available for children up to 16 years old, over 60s and full-time students.

    Supersavers: half-price seats are available for people with disabilities and one companion. It is advisable to book in advance. There is a maximum of eight wheelchair spaces available and one wheelchair space will be held until an hour before the show.

    Standby: best available seats are on sale for $6 from one hour before the performance for people suitable for Saver and Supersaver discounts and thirty minutes before for all other customers.

    Group Booking: there is a ten percent discount for parties of twelve or more.

    School: school parties of ten or more can book $6 standby tickets and will get every tenth ticket free.

    Please note: we are unable to exchange tickets or refund money unless a performance is cancelled due to unforeseen circumstances.