问题 多选题

P、Q两电荷的电场线分布如图,c、d为电场中的两点,一个带电粒子从a运动到b轨迹如图,不计粒子重力,下列说法中正确的是(  )

A.c、d两点的电势相等

B.粒子从a到b的过程中电场力做负功

C.P电荷带负电

D.粒子在运动的过程中受到P的吸引力

答案

A、沿着电场线电势一定降低,所以c点电势大于d点的电势.故A错误.

B、离子从a到b,电场力与速度的夹角为钝角,所以做负功,故B正确.

C、根据电场线的方向,从P出发,终止于Q,所以P带正电,故C正确.

D、电荷所受电场力指向轨迹内侧,所以离子在运动过程中受到P的吸引.故D正确.

故选:BCD.

单项选择题 A1型题
单项选择题

Goal chances came and goal chances went. But two of the world’s highest ranked teams—with some of football’s highest paid players—couldn’t get the ball into the net. And they were playing against sides that only just made it to the World Cup.

With two defeats, one draw and no goals, France collected its newest title since rising to the top of the game four years ago: The worst defending champion in World Cup history.

"I’m very disappointed, and it’s the end of a beautiful story," said a French striker David Trezeguet. "The story began in 1998 and ended today against Denmark. "

France won the 2000 European Championships and was ranked the best team on the planet before the World Cup.

Besides the goalposts and crossbars seeming to be against this unlucky team, France’s game plan has been the same for four years so opponents know it by heart.

Senegal, an African team playing in its first World Cup, surprised everyone by beating France in the opening World Cup match before entering the second round successfully. Uruguay and Denmark followed a similar strategy to stop France, creating a defensive barrier and launching many counter attacks.

Following France, Argentina became the second big name to take an early plane home from this year’s World Cup.

The South Americans were expected to become world champions for a third time. This was particularly because of an impressive display when they lost just one of their 18 qualifying matches.

The team’s 1-0 loss to England on June 7 was the beginning of a nightmare for the players. But even after this surprising defeat, they never thought that they would be going home so soon.

But a 1-1 draw in Argentina’s final group match against Sweden made the unexpected a reality.

Which of the following statements about the French team is NOT true()

A.The French team won a great victory in 2000.

B.The French team improved their way to make goals.

C.The French team was the champion in the last World Cup.

D.In this World Cup, French team’s balls hit the goalposts and crossbars.