题干

如图所示电路,电源电压6 V保持不变,定值电阻的阻值为10Ω,滑动变阻器的最大阻值为20Ω,当开关闭合,滑片由b端向a端移动的过程中,以下说法正确的是(   )

A:当滑片移到a端时,电流表示数为0.2 A

B:当滑片移到中点时,电压表示数为2 V

C:电压表示数与电流表示数的比值不变

D:电压表的示数减少

上一题 下一题 0.0难度 选择题 更新时间:2015-03-02 07:46:03

答案(点此获取答案解析)

C

同类题5

阅读下面短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。

A

Safety and Security Procedures

   Your safety and the security of your personal property(财产) are of the primary concern to those of us who welcome you as our guest. We urge you to take advantage of the following suggestions.

 YOUR VEHICLE

   Lock your vehicle and do not leave money or valuable items inside. We are not responsible for their loss.

TRAVELING

   Be good at noticing things around you when sightseeing or traveling. Stay in heavily traveled areas. Don't display large amounts of cash.

GUEST ROOM SECURITY

   For additional security, use the deadbolt (插锁) provided on your door and make sure the windows are locked. As an additional precautious measure, please secure the secondary locks provided. Do not admit anyone to your room without first making identification. A one-way viewer is provided in your door to assist with identification. If there is any doubt about the person's identity, please contact the Front Desk.

SAFETY BOXES

   Do not leave money or valuables in your room or vehicle. We provide free safety boxes for you. We are not responsible for items left in room valued over $200.

KEYS

   Safeguard your key. Please do not leave it in the door. Do not give your key to others or leave it unattended. Please leave your key at the Front Desk when you check out.

FIRE

   Please familiarize yourself with the nearest fire exits. Report fire or smoke to the hotel operator. In the unlikely event of a fire, please move quickly and calmly to the nearest safe exit and leave the building. Avoid the use of the elevator.

REPORTING

   Please report any suspicious activity, or safety concerns to management.